Changes to update Tomato RAF.

[tomato.git] / release / src / router / flac / src / flac / decode.c

/* flac - Command-line FLAC encoder/decoder
 * Copyright (C) 2000,2001,2002,2003,2004,2005,2006,2007  Josh Coalson
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#if HAVE_CONFIG_H
#  include <config.h>
#endif

#if defined _WIN32 && !defined __CYGWIN__
/* where MSVC puts unlink() */
# include <io.h>
#else
# include <unistd.h>
#endif
#if defined _MSC_VER || defined __MINGW32__
#include <sys/types.h> /* for off_t */
#if _MSC_VER <= 1600 /* @@@ [2G limit] */
#define fseeko fseek
#define ftello ftell
#endif
#endif
#include <errno.h>
#include <math.h> /* for floor() */
#include <stdio.h> /* for FILE etc. */
#include <string.h> /* for strcmp(), strerror() */
#include "FLAC/all.h"
#include "share/grabbag.h"
#include "share/replaygain_synthesis.h"
#include "decode.h"

typedef struct {
#if FLAC__HAS_OGG
        FLAC__bool is_ogg;
        FLAC__bool use_first_serial_number;
        long serial_number;
#endif

        FLAC__bool is_aiff_out;
        FLAC__bool is_wave_out;
        FLAC__bool treat_warnings_as_errors;
        FLAC__bool continue_through_decode_errors;
        FLAC__bool channel_map_none;

        struct {
                replaygain_synthesis_spec_t spec;
                FLAC__bool apply; /* 'spec.apply' is just a request; this 'apply' means we actually parsed the RG tags and are ready to go */
                double scale;
                DitherContext dither_context;
        } replaygain;

        FLAC__bool test_only;
        FLAC__bool analysis_mode;
        analysis_options aopts;
        utils__SkipUntilSpecification *skip_specification;
        utils__SkipUntilSpecification *until_specification; /* a canonicalized value of 0 mean end-of-stream (i.e. --until=-0) */
        utils__CueSpecification *cue_specification;

        const char *inbasefilename;
        const char *infilename;
        const char *outfilename;

        FLAC__uint64 samples_processed;
        unsigned frame_counter;
        FLAC__bool abort_flag;
        FLAC__bool aborting_due_to_until; /* true if we intentionally abort decoding prematurely because we hit the --until point */
        FLAC__bool aborting_due_to_unparseable; /* true if we abort decoding because we hit an unparseable frame */

        FLAC__bool iff_headers_need_fixup;

        FLAC__bool is_big_endian;
        FLAC__bool is_unsigned_samples;
        FLAC__bool got_stream_info;
        FLAC__bool has_md5sum;
        FLAC__uint64 total_samples;
        unsigned bps;
        unsigned channels;
        unsigned sample_rate;
        FLAC__uint32 channel_mask;

        /* these are used only in analyze mode */
        FLAC__uint64 decode_position;

        FLAC__StreamDecoder *decoder;

        FILE *fout;

        foreign_metadata_t *foreign_metadata; /* NULL unless --keep-foreign-metadata requested */
        off_t fm_offset1, fm_offset2, fm_offset3;
} DecoderSession;


static FLAC__bool is_big_endian_host_;


/*
 * local routines
 */
static FLAC__bool DecoderSession_construct(DecoderSession *d, FLAC__bool is_ogg, FLAC__bool use_first_serial_number, long serial_number, FLAC__bool is_aiff_out, FLAC__bool is_wave_out, FLAC__bool treat_warnings_as_errors, FLAC__bool continue_through_decode_errors, FLAC__bool channel_map_none, replaygain_synthesis_spec_t replaygain_synthesis_spec, FLAC__bool analysis_mode, analysis_options aopts, utils__SkipUntilSpecification *skip_specification, utils__SkipUntilSpecification *until_specification, utils__CueSpecification *cue_specification, foreign_metadata_t *foreign_metadata, const char *infilename, const char *outfilename);
static void DecoderSession_destroy(DecoderSession *d, FLAC__bool error_occurred);
static FLAC__bool DecoderSession_init_decoder(DecoderSession *d, const char *infilename);
static FLAC__bool DecoderSession_process(DecoderSession *d);
static int DecoderSession_finish_ok(DecoderSession *d);
static int DecoderSession_finish_error(DecoderSession *d);
static FLAC__bool canonicalize_until_specification(utils__SkipUntilSpecification *spec, const char *inbasefilename, unsigned sample_rate, FLAC__uint64 skip, FLAC__uint64 total_samples_in_input);
static FLAC__bool write_iff_headers(FILE *f, DecoderSession *decoder_session, FLAC__uint64 samples);
static FLAC__bool write_riff_wave_fmt_chunk(FILE *f, FLAC__bool is_waveformatextensible, unsigned bps, unsigned channels, unsigned sample_rate, FLAC__uint32 channel_mask);
static FLAC__bool write_aiff_form_comm_chunk(FILE *f, FLAC__uint64 samples, unsigned bps, unsigned channels, unsigned sample_rate);
static FLAC__bool write_little_endian_uint16(FILE *f, FLAC__uint16 val);
static FLAC__bool write_little_endian_uint32(FILE *f, FLAC__uint32 val);
static FLAC__bool write_big_endian_uint16(FILE *f, FLAC__uint16 val);
static FLAC__bool write_big_endian_uint32(FILE *f, FLAC__uint32 val);
static FLAC__bool write_sane_extended(FILE *f, unsigned val);
static FLAC__bool fixup_iff_headers(DecoderSession *d);
static FLAC__StreamDecoderWriteStatus write_callback(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data);
static void metadata_callback(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data);
static void error_callback(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
static void print_error_with_init_status(const DecoderSession *d, const char *message, FLAC__StreamDecoderInitStatus init_status);
static void print_error_with_state(const DecoderSession *d, const char *message);
static void print_stats(const DecoderSession *decoder_session);


/*
 * public routines
 */
int flac__decode_aiff(const char *infilename, const char *outfilename, FLAC__bool analysis_mode, analysis_options aopts, wav_decode_options_t options)
{
        DecoderSession decoder_session;

        if(!
                DecoderSession_construct(
                        &decoder_session,
#if FLAC__HAS_OGG
                        options.common.is_ogg,
                        options.common.use_first_serial_number,
                        options.common.serial_number,
#else
                        /*is_ogg=*/false,
                        /*use_first_serial_number=*/false,
                        /*serial_number=*/0,
#endif
                        /*is_aiff_out=*/true,
                        /*is_wave_out=*/false,
                        options.common.treat_warnings_as_errors,
                        options.common.continue_through_decode_errors,
                        options.common.channel_map_none,
                        options.common.replaygain_synthesis_spec,
                        analysis_mode,
                        aopts,
                        &options.common.skip_specification,
                        &options.common.until_specification,
                        options.common.has_cue_specification? &options.common.cue_specification : 0,
                        options.foreign_metadata,
                        infilename,
                        outfilename
                )
        )
                return 1;

        if(!DecoderSession_init_decoder(&decoder_session, infilename))
                return DecoderSession_finish_error(&decoder_session);

        if(!DecoderSession_process(&decoder_session))
                return DecoderSession_finish_error(&decoder_session);

        return DecoderSession_finish_ok(&decoder_session);
}

int flac__decode_wav(const char *infilename, const char *outfilename, FLAC__bool analysis_mode, analysis_options aopts, wav_decode_options_t options)
{
        DecoderSession decoder_session;

        if(!
                DecoderSession_construct(
                        &decoder_session,
#if FLAC__HAS_OGG
                        options.common.is_ogg,
                        options.common.use_first_serial_number,
                        options.common.serial_number,
#else
                        /*is_ogg=*/false,
                        /*use_first_serial_number=*/false,
                        /*serial_number=*/0,
#endif
                        /*is_aiff_out=*/false,
                        /*is_wave_out=*/true,
                        options.common.treat_warnings_as_errors,
                        options.common.continue_through_decode_errors,
                        options.common.channel_map_none,
                        options.common.replaygain_synthesis_spec,
                        analysis_mode,
                        aopts,
                        &options.common.skip_specification,
                        &options.common.until_specification,
                        options.common.has_cue_specification? &options.common.cue_specification : 0,
                        options.foreign_metadata,
                        infilename,
                        outfilename
                )
        )
                return 1;

        if(!DecoderSession_init_decoder(&decoder_session, infilename))
                return DecoderSession_finish_error(&decoder_session);

        if(!DecoderSession_process(&decoder_session))
                return DecoderSession_finish_error(&decoder_session);

        return DecoderSession_finish_ok(&decoder_session);
}

int flac__decode_raw(const char *infilename, const char *outfilename, FLAC__bool analysis_mode, analysis_options aopts, raw_decode_options_t options)
{
        DecoderSession decoder_session;

        decoder_session.is_big_endian = options.is_big_endian;
        decoder_session.is_unsigned_samples = options.is_unsigned_samples;

        if(!
                DecoderSession_construct(
                        &decoder_session,
#if FLAC__HAS_OGG
                        options.common.is_ogg,
                        options.common.use_first_serial_number,
                        options.common.serial_number,
#else
                        /*is_ogg=*/false,
                        /*use_first_serial_number=*/false,
                        /*serial_number=*/0,
#endif
                        /*is_aiff_out=*/false,
                        /*is_wave_out=*/false,
                        options.common.treat_warnings_as_errors,
                        options.common.continue_through_decode_errors,
                        options.common.channel_map_none,
                        options.common.replaygain_synthesis_spec,
                        analysis_mode,
                        aopts,
                        &options.common.skip_specification,
                        &options.common.until_specification,
                        options.common.has_cue_specification? &options.common.cue_specification : 0,
                        /*foreign_metadata=*/NULL,
                        infilename,
                        outfilename
                )
        )
                return 1;

        if(!DecoderSession_init_decoder(&decoder_session, infilename))
                return DecoderSession_finish_error(&decoder_session);

        if(!DecoderSession_process(&decoder_session))
                return DecoderSession_finish_error(&decoder_session);

        return DecoderSession_finish_ok(&decoder_session);
}

FLAC__bool DecoderSession_construct(DecoderSession *d, FLAC__bool is_ogg, FLAC__bool use_first_serial_number, long serial_number, FLAC__bool is_aiff_out, FLAC__bool is_wave_out, FLAC__bool treat_warnings_as_errors, FLAC__bool continue_through_decode_errors, FLAC__bool channel_map_none, replaygain_synthesis_spec_t replaygain_synthesis_spec, FLAC__bool analysis_mode, analysis_options aopts, utils__SkipUntilSpecification *skip_specification, utils__SkipUntilSpecification *until_specification, utils__CueSpecification *cue_specification, foreign_metadata_t *foreign_metadata, const char *infilename, const char *outfilename)
{
#if FLAC__HAS_OGG
        d->is_ogg = is_ogg;
        d->use_first_serial_number = use_first_serial_number;
        d->serial_number = serial_number;
#else
        (void)is_ogg;
        (void)use_first_serial_number;
        (void)serial_number;
#endif

        d->is_aiff_out = is_aiff_out;
        d->is_wave_out = is_wave_out;
        d->treat_warnings_as_errors = treat_warnings_as_errors;
        d->continue_through_decode_errors = continue_through_decode_errors;
        d->channel_map_none = channel_map_none;
        d->replaygain.spec = replaygain_synthesis_spec;
        d->replaygain.apply = false;
        d->replaygain.scale = 0.0;
        /* d->replaygain.dither_context gets initialized later once we know the sample resolution */
        d->test_only = (0 == outfilename);
        d->analysis_mode = analysis_mode;
        d->aopts = aopts;
        d->skip_specification = skip_specification;
        d->until_specification = until_specification;
        d->cue_specification = cue_specification;

        d->inbasefilename = grabbag__file_get_basename(infilename);
        d->infilename = infilename;
        d->outfilename = outfilename;

        d->samples_processed = 0;
        d->frame_counter = 0;
        d->abort_flag = false;
        d->aborting_due_to_until = false;
        d->aborting_due_to_unparseable = false;

        d->iff_headers_need_fixup = false;

        d->total_samples = 0;
        d->got_stream_info = false;
        d->has_md5sum = false;
        d->bps = 0;
        d->channels = 0;
        d->sample_rate = 0;
        d->channel_mask = 0;

        d->decode_position = 0;

        d->decoder = 0;

        d->fout = 0; /* initialized with an open file later if necessary */

        d->foreign_metadata = foreign_metadata;

        FLAC__ASSERT(!(d->test_only && d->analysis_mode));

        if(!d->test_only) {
                if(0 == strcmp(outfilename, "-")) {
                        d->fout = grabbag__file_get_binary_stdout();
                }
                else {
                        if(0 == (d->fout = fopen(outfilename, "wb"))) {
                                flac__utils_printf(stderr, 1, "%s: ERROR: can't open output file %s: %s\n", d->inbasefilename, outfilename, strerror(errno));
                                DecoderSession_destroy(d, /*error_occurred=*/true);
                                return false;
                        }
                }
        }

        if(analysis_mode)
                flac__analyze_init(aopts);

        return true;
}

void DecoderSession_destroy(DecoderSession *d, FLAC__bool error_occurred)
{
        if(0 != d->fout && d->fout != stdout) {
                fclose(d->fout);
                if(error_occurred)
                        unlink(d->outfilename);
        }
}

FLAC__bool DecoderSession_init_decoder(DecoderSession *decoder_session, const char *infilename)
{
        FLAC__StreamDecoderInitStatus init_status;
        FLAC__uint32 test = 1;

        is_big_endian_host_ = (*((FLAC__byte*)(&test)))? false : true;

        if(!decoder_session->analysis_mode && !decoder_session->test_only && (decoder_session->is_wave_out || decoder_session->is_aiff_out)) {
                if(decoder_session->foreign_metadata) {
                        const char *error;
                        if(!flac__foreign_metadata_read_from_flac(decoder_session->foreign_metadata, infilename, &error)) {
                                flac__utils_printf(stderr, 1, "%s: ERROR reading foreign metadata: %s\n", decoder_session->inbasefilename, error);
                                return false;
                        }
                }
        }

        decoder_session->decoder = FLAC__stream_decoder_new();

        if(0 == decoder_session->decoder) {
                flac__utils_printf(stderr, 1, "%s: ERROR creating the decoder instance\n", decoder_session->inbasefilename);
                return false;
        }

        FLAC__stream_decoder_set_md5_checking(decoder_session->decoder, true);
        if (0 != decoder_session->cue_specification)
                FLAC__stream_decoder_set_metadata_respond(decoder_session->decoder, FLAC__METADATA_TYPE_CUESHEET);
        if (decoder_session->replaygain.spec.apply)
                FLAC__stream_decoder_set_metadata_respond(decoder_session->decoder, FLAC__METADATA_TYPE_VORBIS_COMMENT);

#if FLAC__HAS_OGG
        if(decoder_session->is_ogg) {
                if(!decoder_session->use_first_serial_number)
                        FLAC__stream_decoder_set_ogg_serial_number(decoder_session->decoder, decoder_session->serial_number);
                init_status = FLAC__stream_decoder_init_ogg_file(decoder_session->decoder, strcmp(infilename, "-")? infilename : 0, write_callback, metadata_callback, error_callback, /*client_data=*/decoder_session);
        }
        else
#endif
        {
                init_status = FLAC__stream_decoder_init_file(decoder_session->decoder, strcmp(infilename, "-")? infilename : 0, write_callback, metadata_callback, error_callback, /*client_data=*/decoder_session);
        }

        if(init_status != FLAC__STREAM_DECODER_INIT_STATUS_OK) {
                print_error_with_init_status(decoder_session, "ERROR initializing decoder", init_status);
                return false;
        }

        return true;
}

FLAC__bool DecoderSession_process(DecoderSession *d)
{
        if(!FLAC__stream_decoder_process_until_end_of_metadata(d->decoder)) {
                flac__utils_printf(stderr, 2, "\n");
                print_error_with_state(d, "ERROR while decoding metadata");
                return false;
        }
        if(FLAC__stream_decoder_get_state(d->decoder) > FLAC__STREAM_DECODER_END_OF_STREAM) {
                flac__utils_printf(stderr, 2, "\n");
                print_error_with_state(d, "ERROR during metadata decoding");
                if(!d->continue_through_decode_errors)
                        return false;
        }

        if(d->abort_flag)
                return false;

        /* set channel mapping */
        if(!d->channel_map_none) {
                /* currently FLAC order matches SMPTE/WAVEFORMATEXTENSIBLE order, so no reordering is necessary; see encode.c */
                /* only the channel mask must be set if it was not already picked up from the WAVEFORMATEXTENSIBLE_CHANNEL_MASK tag */
                if(d->channels == 1) {
                        if(d->channel_mask == 0)
                                d->channel_mask = 0x0001;
                }
                else if(d->channels == 2) {
                        if(d->channel_mask == 0)
                                d->channel_mask = 0x0003;
                }
                else if(d->channels == 3) {
                        if(d->channel_mask == 0)
                                d->channel_mask = 0x0007;
                }
                else if(d->channels == 4) {
                        if(d->channel_mask == 0)
                                d->channel_mask = 0x0033;
                }
                else if(d->channels == 5) {
                        if(d->channel_mask == 0)
                                d->channel_mask = 0x0607;
                }
                else if(d->channels == 6) {
                        if(d->channel_mask == 0)
                                d->channel_mask = 0x060f;
                }
        }

        /* write the WAVE/AIFF headers if necessary */
        if(!d->analysis_mode && !d->test_only && (d->is_wave_out || d->is_aiff_out)) {
                if(!write_iff_headers(d->fout, d, d->total_samples)) {
                        d->abort_flag = true;
                        return false;
                }
        }

        if(d->skip_specification->value.samples > 0) {
                const FLAC__uint64 skip = (FLAC__uint64)d->skip_specification->value.samples;

                if(!FLAC__stream_decoder_seek_absolute(d->decoder, skip)) {
                        print_error_with_state(d, "ERROR seeking while skipping bytes");
                        return false;
                }
        }
        if(!FLAC__stream_decoder_process_until_end_of_stream(d->decoder) && !d->aborting_due_to_until) {
                flac__utils_printf(stderr, 2, "\n");
                print_error_with_state(d, "ERROR while decoding data");
                if(!d->continue_through_decode_errors)
                        return false;
        }
        if(
                (d->abort_flag && !(d->aborting_due_to_until || d->continue_through_decode_errors)) ||
                (FLAC__stream_decoder_get_state(d->decoder) > FLAC__STREAM_DECODER_END_OF_STREAM && !d->aborting_due_to_until)
        ) {
                flac__utils_printf(stderr, 2, "\n");
                print_error_with_state(d, "ERROR during decoding");
                return false;
        }

        if(!d->analysis_mode && !d->test_only && (d->is_wave_out || d->is_aiff_out) && ((d->total_samples * d->channels * ((d->bps+7)/8)) & 1)) {
                if(flac__utils_fwrite("\000", 1, 1, d->fout) != 1) {
                        print_error_with_state(d, d->is_wave_out?
                                "ERROR writing pad byte to WAVE data chunk" :
                                "ERROR writing pad byte to AIFF SSND chunk"
                        );
                        return false;
                }
        }

        return true;
}

int DecoderSession_finish_ok(DecoderSession *d)
{
        FLAC__bool ok = true, md5_failure = false;

        if(d->decoder) {
                md5_failure = !FLAC__stream_decoder_finish(d->decoder) && !d->aborting_due_to_until;
                print_stats(d);
                FLAC__stream_decoder_delete(d->decoder);
        }
        if(d->analysis_mode)
                flac__analyze_finish(d->aopts);
        if(md5_failure) {
                flac__utils_printf(stderr, 1, "\r%s: ERROR, MD5 signature mismatch\n", d->inbasefilename);
                ok = d->continue_through_decode_errors;
        }
        else {
                if(!d->got_stream_info) {
                        flac__utils_printf(stderr, 1, "\r%s: WARNING, cannot check MD5 signature since there was no STREAMINFO\n", d->inbasefilename);
                        ok = !d->treat_warnings_as_errors;
                }
                else if(!d->has_md5sum) {
                        flac__utils_printf(stderr, 1, "\r%s: WARNING, cannot check MD5 signature since it was unset in the STREAMINFO\n", d->inbasefilename);
                        ok = !d->treat_warnings_as_errors;
                }
                flac__utils_printf(stderr, 2, "\r%s: %s         \n", d->inbasefilename, d->test_only? "ok           ":d->analysis_mode?"done           ":"done");
        }
        DecoderSession_destroy(d, /*error_occurred=*/!ok);
        if(!d->analysis_mode && !d->test_only && (d->is_wave_out || d->is_aiff_out)) {
                if(d->iff_headers_need_fixup || (!d->got_stream_info && strcmp(d->outfilename, "-"))) {
                        if(!fixup_iff_headers(d))
                                return 1;
                }
                if(d->foreign_metadata) {
                        const char *error;
                        if(!flac__foreign_metadata_write_to_iff(d->foreign_metadata, d->infilename, d->outfilename, d->fm_offset1, d->fm_offset2, d->fm_offset3, &error)) {
                                flac__utils_printf(stderr, 1, "ERROR updating foreign metadata from %s to %s: %s\n", d->infilename, d->outfilename, error);
                                return 1;
                        }
                }
        }
        return ok? 0 : 1;
}

int DecoderSession_finish_error(DecoderSession *d)
{
        if(d->decoder) {
                (void)FLAC__stream_decoder_finish(d->decoder);
                FLAC__stream_decoder_delete(d->decoder);
        }
        if(d->analysis_mode)
                flac__analyze_finish(d->aopts);
        DecoderSession_destroy(d, /*error_occurred=*/true);
        return 1;
}

FLAC__bool canonicalize_until_specification(utils__SkipUntilSpecification *spec, const char *inbasefilename, unsigned sample_rate, FLAC__uint64 skip, FLAC__uint64 total_samples_in_input)
{
        /* convert from mm:ss.sss to sample number if necessary */
        flac__utils_canonicalize_skip_until_specification(spec, sample_rate);

        /* special case: if "--until=-0", use the special value '0' to mean "end-of-stream" */
        if(spec->is_relative && spec->value.samples == 0) {
                spec->is_relative = false;
                return true;
        }

        /* in any other case the total samples in the input must be known */
        if(total_samples_in_input == 0) {
                flac__utils_printf(stderr, 1, "%s: ERROR, cannot use --until when FLAC metadata has total sample count of 0\n", inbasefilename);
                return false;
        }

        FLAC__ASSERT(spec->value_is_samples);

        /* convert relative specifications to absolute */
        if(spec->is_relative) {
                if(spec->value.samples <= 0)
                        spec->value.samples += (FLAC__int64)total_samples_in_input;
                else
                        spec->value.samples += skip;
                spec->is_relative = false;
        }

        /* error check */
        if(spec->value.samples < 0) {
                flac__utils_printf(stderr, 1, "%s: ERROR, --until value is before beginning of input\n", inbasefilename);
                return false;
        }
        if((FLAC__uint64)spec->value.samples <= skip) {
                flac__utils_printf(stderr, 1, "%s: ERROR, --until value is before --skip point\n", inbasefilename);
                return false;
        }
        if((FLAC__uint64)spec->value.samples > total_samples_in_input) {
                flac__utils_printf(stderr, 1, "%s: ERROR, --until value is after end of input\n", inbasefilename);
                return false;
        }

        return true;
}

FLAC__bool write_iff_headers(FILE *f, DecoderSession *decoder_session, FLAC__uint64 samples)
{
        const char *fmt_desc = decoder_session->is_wave_out? "WAVE" : "AIFF";
        const FLAC__bool is_waveformatextensible = decoder_session->is_wave_out && (decoder_session->channel_mask == 2 || decoder_session->channel_mask > 3 || decoder_session->bps%8 || decoder_session->channels > 2);
        FLAC__uint64 data_size = samples * decoder_session->channels * ((decoder_session->bps+7)/8);
        const FLAC__uint32 aligned_data_size = (FLAC__uint32)((data_size+1) & (~1U)); /* we'll check for overflow later */

        unsigned foreign_metadata_size = 0; /* size of all non-audio non-fmt/COMM foreign metadata chunks */
        foreign_metadata_t *fm = decoder_session->foreign_metadata;
        size_t i;

        if(samples == 0) {
                if(f == stdout) {
                        flac__utils_printf(stderr, 1, "%s: WARNING, don't have accurate sample count available for %s header.\n", decoder_session->inbasefilename, fmt_desc);
                        flac__utils_printf(stderr, 1, "             Generated %s file will have a data chunk size of 0.  Try\n", fmt_desc);
                        flac__utils_printf(stderr, 1, "             decoding directly to a file instead.\n");
                        if(decoder_session->treat_warnings_as_errors)
                                return false;
                }
                else {
                        decoder_session->iff_headers_need_fixup = true;
                }
        }

        if(fm) {
                FLAC__ASSERT(fm->format_block);
                FLAC__ASSERT(fm->audio_block);
                FLAC__ASSERT(fm->format_block < fm->audio_block);
                /* calc foreign metadata size; for RIFF/AIFF we always skip the first chunk, format chunk, and sound chunk since we write our own */
                for(i = 1; i < fm->num_blocks; i++) {
                        if(i != fm->format_block && i != fm->audio_block)
                                foreign_metadata_size += fm->blocks[i].size;
                }
        }

        if(data_size + foreign_metadata_size + 60/*worst-case*/ >= 0xFFFFFFF4) {
                flac__utils_printf(stderr, 1, "%s: ERROR: stream is too big to fit in a single %s file\n", decoder_session->inbasefilename, fmt_desc);
                return false;
        }

        if(decoder_session->is_wave_out) {
                if(flac__utils_fwrite("RIFF", 1, 4, f) != 4)
                        return false;

                if(!write_little_endian_uint32(f, foreign_metadata_size + aligned_data_size + (is_waveformatextensible?60:36))) /* filesize-8 */
                        return false;

                if(flac__utils_fwrite("WAVE", 1, 4, f) != 4)
                        return false;

                decoder_session->fm_offset1 = ftello(f);

                if(fm) {
                        /* seek forward to {allocate} or {skip over already-written chunks} before "fmt " */
                        for(i = 1; i < fm->format_block; i++) {
                                if(fseeko(f, fm->blocks[i].size, SEEK_CUR) < 0) {
                                        flac__utils_printf(stderr, 1, "%s: ERROR: allocating/skipping foreign metadata before \"fmt \"\n", decoder_session->inbasefilename);
                                        return false;
                                }
                        }
                }

                if(!write_riff_wave_fmt_chunk(f, is_waveformatextensible, decoder_session->bps, decoder_session->channels, decoder_session->sample_rate, decoder_session->channel_mask))
                        return false;

                decoder_session->fm_offset2 = ftello(f);

                if(fm) {
                        /* seek forward to {allocate} or {skip over already-written chunks} after "fmt " but before "data" */
                        for(i = fm->format_block+1; i < fm->audio_block; i++) {
                                if(fseeko(f, fm->blocks[i].size, SEEK_CUR) < 0) {
                                        flac__utils_printf(stderr, 1, "%s: ERROR: allocating/skipping foreign metadata after \"fmt \"\n", decoder_session->inbasefilename);
                                        return false;
                                }
                        }
                }

                if(flac__utils_fwrite("data", 1, 4, f) != 4)
                        return false;

                if(!write_little_endian_uint32(f, (FLAC__uint32)data_size)) /* data size */
                        return false;

                decoder_session->fm_offset3 = ftello(f) + aligned_data_size;
        }
        else {
                FLAC__uint32 ssnd_offset_size = (fm? fm->ssnd_offset_size : 0);

                if(flac__utils_fwrite("FORM", 1, 4, f) != 4)
                        return false;

                if(!write_big_endian_uint32(f, foreign_metadata_size + aligned_data_size + 46 + ssnd_offset_size)) /* filesize-8 */
                        return false;

                if(flac__utils_fwrite("AIFF", 1, 4, f) != 4)
                        return false;

                decoder_session->fm_offset1 = ftello(f);

                if(fm) {
                        /* seek forward to {allocate} or {skip over already-written chunks} before "COMM" */
                        for(i = 1; i < fm->format_block; i++) {
                                if(fseeko(f, fm->blocks[i].size, SEEK_CUR) < 0) {
                                        flac__utils_printf(stderr, 1, "%s: ERROR: allocating/skipping foreign metadata before \"COMM\"\n", decoder_session->inbasefilename);
                                        return false;
                                }
                        }
                }

                if(!write_aiff_form_comm_chunk(f, samples, decoder_session->bps, decoder_session->channels, decoder_session->sample_rate))
                        return false;

                decoder_session->fm_offset2 = ftello(f);

                if(fm) {
                        /* seek forward to {allocate} or {skip over already-written chunks} after "COMM" but before "SSND" */
                        for(i = fm->format_block+1; i < fm->audio_block; i++) {
                                if(fseeko(f, fm->blocks[i].size, SEEK_CUR) < 0) {
                                        flac__utils_printf(stderr, 1, "%s: ERROR: allocating/skipping foreign metadata after \"COMM\"\n", decoder_session->inbasefilename);
                                        return false;
                                }
                        }
                }

                if(flac__utils_fwrite("SSND", 1, 4, f) != 4)
                        return false;

                if(!write_big_endian_uint32(f, (FLAC__uint32)data_size + 8 + ssnd_offset_size)) /* data size */
                        return false;

                if(!write_big_endian_uint32(f, ssnd_offset_size))
                        return false;

                if(!write_big_endian_uint32(f, 0/*block_size*/))
                        return false;

                if(ssnd_offset_size) {
                        /* seek forward to {allocate} or {skip over already-written} SSND offset */
                        if(fseeko(f, ssnd_offset_size, SEEK_CUR) < 0) {
                                flac__utils_printf(stderr, 1, "%s: ERROR: allocating/skipping \"SSND\" offset\n", decoder_session->inbasefilename);
                                return false;
                        }
                }

                decoder_session->fm_offset3 = ftello(f) + aligned_data_size;
        }

        return true;
}

FLAC__bool write_riff_wave_fmt_chunk(FILE *f, FLAC__bool is_waveformatextensible, unsigned bps, unsigned channels, unsigned sample_rate, FLAC__uint32 channel_mask)
{
        if(flac__utils_fwrite("fmt ", 1, 4, f) != 4)
                return false;

        if(!write_little_endian_uint32(f, is_waveformatextensible? 40 : 16)) /* chunk size */
                return false;

        if(!write_little_endian_uint16(f, (FLAC__uint16)(is_waveformatextensible? 65534 : 1))) /* compression code */
                return false;

        if(!write_little_endian_uint16(f, (FLAC__uint16)channels))
                return false;

        if(!write_little_endian_uint32(f, sample_rate))
                return false;

        if(!write_little_endian_uint32(f, sample_rate * channels * ((bps+7) / 8)))
                return false;

        if(!write_little_endian_uint16(f, (FLAC__uint16)(channels * ((bps+7) / 8)))) /* block align */
                return false;

        if(!write_little_endian_uint16(f, (FLAC__uint16)(((bps+7)/8)*8))) /* bits per sample */
                return false;

        if(is_waveformatextensible) {
                if(!write_little_endian_uint16(f, (FLAC__uint16)22)) /* cbSize */
                        return false;

                if(!write_little_endian_uint16(f, (FLAC__uint16)bps)) /* validBitsPerSample */
                        return false;

                if(!write_little_endian_uint32(f, channel_mask))
                        return false;

                /* GUID = {0x00000001, 0x0000, 0x0010, {0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}} */
                if(flac__utils_fwrite("\x01\x00\x00\x00\x00\x00\x10\x00\x80\x00\x00\xaa\x00\x38\x9b\x71", 1, 16, f) != 16)
                        return false;
        }

        return true;
}

FLAC__bool write_aiff_form_comm_chunk(FILE *f, FLAC__uint64 samples, unsigned bps, unsigned channels, unsigned sample_rate)
{
        FLAC__ASSERT(samples <= 0xffffffff);

        if(flac__utils_fwrite("COMM", 1, 4, f) != 4)
                return false;

        if(!write_big_endian_uint32(f, 18)) /* chunk size = 18 */
                return false;

        if(!write_big_endian_uint16(f, (FLAC__uint16)channels))
                return false;

        if(!write_big_endian_uint32(f, (FLAC__uint32)samples))
                return false;

        if(!write_big_endian_uint16(f, (FLAC__uint16)bps))
                return false;

        if(!write_sane_extended(f, sample_rate))
                return false;

        return true;
}

FLAC__bool write_little_endian_uint16(FILE *f, FLAC__uint16 val)
{
        FLAC__byte *b = (FLAC__byte*)(&val);
        if(is_big_endian_host_) {
                FLAC__byte tmp;
                tmp = b[1]; b[1] = b[0]; b[0] = tmp;
        }
        return flac__utils_fwrite(b, 1, 2, f) == 2;
}

FLAC__bool write_little_endian_uint32(FILE *f, FLAC__uint32 val)
{
        FLAC__byte *b = (FLAC__byte*)(&val);
        if(is_big_endian_host_) {
                FLAC__byte tmp;
                tmp = b[3]; b[3] = b[0]; b[0] = tmp;
                tmp = b[2]; b[2] = b[1]; b[1] = tmp;
        }
        return flac__utils_fwrite(b, 1, 4, f) == 4;
}

FLAC__bool write_big_endian_uint16(FILE *f, FLAC__uint16 val)
{
        FLAC__byte *b = (FLAC__byte*)(&val);
        if(!is_big_endian_host_) {
                FLAC__byte tmp;
                tmp = b[1]; b[1] = b[0]; b[0] = tmp;
        }
        return flac__utils_fwrite(b, 1, 2, f) == 2;
}

FLAC__bool write_big_endian_uint32(FILE *f, FLAC__uint32 val)
{
        FLAC__byte *b = (FLAC__byte*)(&val);
        if(!is_big_endian_host_) {
                FLAC__byte tmp;
                tmp = b[3]; b[3] = b[0]; b[0] = tmp;
                tmp = b[2]; b[2] = b[1]; b[1] = tmp;
        }
        return flac__utils_fwrite(b, 1, 4, f) == 4;
}

FLAC__bool write_sane_extended(FILE *f, unsigned val)
        /* Write to 'f' a SANE extended representation of 'val'.  Return false if
        * the write succeeds; return true otherwise.
        *
        * SANE extended is an 80-bit IEEE-754 representation with sign bit, 15 bits
        * of exponent, and 64 bits of significand (mantissa).  Unlike most IEEE-754
        * representations, it does not imply a 1 above the MSB of the significand.
        *
        * Preconditions:
        *  val!=0U
        */
{
        unsigned int shift, exponent;

        FLAC__ASSERT(val!=0U); /* handling 0 would require a special case */

        for(shift= 0U; (val>>(31-shift))==0U; ++shift)
                ;
        val<<= shift;
        exponent= 63U-(shift+32U); /* add 32 for unused second word */

        if(!write_big_endian_uint16(f, (FLAC__uint16)(exponent+0x3FFF)))
                return false;
        if(!write_big_endian_uint32(f, val))
                return false;
        if(!write_big_endian_uint32(f, 0)) /* unused second word */
                return false;

        return true;
}

FLAC__bool fixup_iff_headers(DecoderSession *d)
{
        const char *fmt_desc = (d->is_wave_out? "WAVE" : "AIFF");
        FILE *f = fopen(d->outfilename, "r+b"); /* stream is positioned at beginning of file */

        if(0 == f) {
                flac__utils_printf(stderr, 1, "ERROR, couldn't open file %s while fixing up %s chunk size: %s\n", d->outfilename, fmt_desc, strerror(errno));
                return false;
        }

        if(!write_iff_headers(f, d, d->samples_processed)) {
                fclose(f);
                return false;
        }

        fclose(f);
        return true;
}

FLAC__StreamDecoderWriteStatus write_callback(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
{
        DecoderSession *decoder_session = (DecoderSession*)client_data;
        FILE *fout = decoder_session->fout;
        const unsigned bps = frame->header.bits_per_sample, channels = frame->header.channels;
        const unsigned shift = ((decoder_session->is_wave_out || decoder_session->is_aiff_out) && (bps%8)? 8-(bps%8): 0);
        FLAC__bool is_big_endian = (decoder_session->is_aiff_out? true : (decoder_session->is_wave_out? false : decoder_session->is_big_endian));
        FLAC__bool is_unsigned_samples = (decoder_session->is_aiff_out? false : (decoder_session->is_wave_out? bps<=8 : decoder_session->is_unsigned_samples));
        unsigned wide_samples = frame->header.blocksize, wide_sample, sample, channel, byte;
        unsigned frame_bytes = 0;
        static FLAC__int8 s8buffer[FLAC__MAX_BLOCK_SIZE * FLAC__MAX_CHANNELS * sizeof(FLAC__int32)]; /* WATCHOUT: can be up to 2 megs */
        FLAC__uint8  *u8buffer  = (FLAC__uint8  *)s8buffer;
        FLAC__int16  *s16buffer = (FLAC__int16  *)s8buffer;
        FLAC__uint16 *u16buffer = (FLAC__uint16 *)s8buffer;
        FLAC__int32  *s32buffer = (FLAC__int32  *)s8buffer;
        FLAC__uint32 *u32buffer = (FLAC__uint32 *)s8buffer;
        size_t bytes_to_write = 0;

        (void)decoder;

        if(decoder_session->abort_flag)
                return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;

        /* sanity-check the bits-per-sample */
        if(decoder_session->bps) {
                if(bps != decoder_session->bps) {
                        if(decoder_session->got_stream_info)
                                flac__utils_printf(stderr, 1, "%s: ERROR, bits-per-sample is %u in frame but %u in STREAMINFO\n", decoder_session->inbasefilename, bps, decoder_session->bps);
                        else
                                flac__utils_printf(stderr, 1, "%s: ERROR, bits-per-sample is %u in this frame but %u in previous frames\n", decoder_session->inbasefilename, bps, decoder_session->bps);
                        if(!decoder_session->continue_through_decode_errors)
                                return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
                }
        }
        else {
                /* must not have gotten STREAMINFO, save the bps from the frame header */
                FLAC__ASSERT(!decoder_session->got_stream_info);
                decoder_session->bps = bps;
        }

        /* sanity-check the #channels */
        if(decoder_session->channels) {
                if(channels != decoder_session->channels) {
                        if(decoder_session->got_stream_info)
                                flac__utils_printf(stderr, 1, "%s: ERROR, channels is %u in frame but %u in STREAMINFO\n", decoder_session->inbasefilename, channels, decoder_session->channels);
                        else
                                flac__utils_printf(stderr, 1, "%s: ERROR, channels is %u in this frame but %u in previous frames\n", decoder_session->inbasefilename, channels, decoder_session->channels);
                        if(!decoder_session->continue_through_decode_errors)
                                return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
                }
        }
        else {
                /* must not have gotten STREAMINFO, save the #channels from the frame header */
                FLAC__ASSERT(!decoder_session->got_stream_info);
                decoder_session->channels = channels;
        }

        /* sanity-check the sample rate */
        if(decoder_session->sample_rate) {
                if(frame->header.sample_rate != decoder_session->sample_rate) {
                        if(decoder_session->got_stream_info)
                                flac__utils_printf(stderr, 1, "%s: ERROR, sample rate is %u in frame but %u in STREAMINFO\n", decoder_session->inbasefilename, frame->header.sample_rate, decoder_session->sample_rate);
                        else
                                flac__utils_printf(stderr, 1, "%s: ERROR, sample rate is %u in this frame but %u in previous frames\n", decoder_session->inbasefilename, frame->header.sample_rate, decoder_session->sample_rate);
                        if(!decoder_session->continue_through_decode_errors)
                                return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
                }
        }
        else {
                /* must not have gotten STREAMINFO, save the sample rate from the frame header */
                FLAC__ASSERT(!decoder_session->got_stream_info);
                decoder_session->sample_rate = frame->header.sample_rate;
        }

        /*
         * limit the number of samples to accept based on --until
         */
        FLAC__ASSERT(!decoder_session->skip_specification->is_relative);
        /* if we never got the total_samples from the metadata, the skip and until specs would never have been canonicalized, so protect against that: */
        if(decoder_session->skip_specification->is_relative) {
                if(decoder_session->skip_specification->value.samples == 0) /* special case for when no --skip was given */
                        decoder_session->skip_specification->is_relative = false; /* convert to our meaning of beginning-of-stream */
                else {
                        flac__utils_printf(stderr, 1, "%s: ERROR, cannot use --skip because the total sample count was not found in the metadata\n", decoder_session->inbasefilename);
                        return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
                }
        }
        if(decoder_session->until_specification->is_relative) {
                if(decoder_session->until_specification->value.samples == 0) /* special case for when no --until was given */
                        decoder_session->until_specification->is_relative = false; /* convert to our meaning of end-of-stream */
                else {
                        flac__utils_printf(stderr, 1, "%s: ERROR, cannot use --until because the total sample count was not found in the metadata\n", decoder_session->inbasefilename);
                        return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
                }
        }
        FLAC__ASSERT(decoder_session->skip_specification->value.samples >= 0);
        FLAC__ASSERT(decoder_session->until_specification->value.samples >= 0);
        if(decoder_session->until_specification->value.samples > 0) {
                const FLAC__uint64 skip = (FLAC__uint64)decoder_session->skip_specification->value.samples;
                const FLAC__uint64 until = (FLAC__uint64)decoder_session->until_specification->value.samples;
                const FLAC__uint64 input_samples_passed = skip + decoder_session->samples_processed;
                FLAC__ASSERT(until >= input_samples_passed);
                if(input_samples_passed + wide_samples > until)
                        wide_samples = (unsigned)(until - input_samples_passed);
                if (wide_samples == 0) {
                        decoder_session->abort_flag = true;
                        decoder_session->aborting_due_to_until = true;
                        return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
                }
        }

        if(decoder_session->analysis_mode) {
                FLAC__uint64 dpos;
                FLAC__stream_decoder_get_decode_position(decoder_session->decoder, &dpos);
                frame_bytes = (unsigned)(dpos-decoder_session->decode_position);
                decoder_session->decode_position = dpos;
        }

        if(wide_samples > 0) {
                decoder_session->samples_processed += wide_samples;
                decoder_session->frame_counter++;

                if(!(decoder_session->frame_counter & 0x3f))
                        print_stats(decoder_session);

                if(decoder_session->analysis_mode) {
                        flac__analyze_frame(frame, decoder_session->frame_counter-1, decoder_session->decode_position-frame_bytes, frame_bytes, decoder_session->aopts, fout);
                }
                else if(!decoder_session->test_only) {
                        if(shift && !decoder_session->replaygain.apply) {
                                for(wide_sample = 0; wide_sample < wide_samples; wide_sample++)
                                        for(channel = 0; channel < channels; channel++)
                                                ((FLAC__int32**)buffer)[channel][wide_sample] <<= shift;/*@@@@@@un-const'ing the buffer is hacky but safe*/
                        }
                        if(decoder_session->replaygain.apply) {
                                bytes_to_write = FLAC__replaygain_synthesis__apply_gain(
                                        u8buffer,
                                        !is_big_endian,
                                        is_unsigned_samples,
                                        buffer,
                                        wide_samples,
                                        channels,
                                        bps, /* source_bps */
                                        bps+shift, /* target_bps */
                                        decoder_session->replaygain.scale,
                                        decoder_session->replaygain.spec.limiter == RGSS_LIMIT__HARD, /* hard_limit */
                                        decoder_session->replaygain.spec.noise_shaping != NOISE_SHAPING_NONE, /* do_dithering */
                                        &decoder_session->replaygain.dither_context
                                );
                        }
                        /* first some special code for common cases */
                        else if(is_big_endian == is_big_endian_host_ && !is_unsigned_samples && channels == 2 && bps+shift == 16) {
                                FLAC__int16 *buf1_ = s16buffer + 1;
                                if(is_big_endian)
                                        memcpy(s16buffer, ((FLAC__byte*)(buffer[0]))+2, sizeof(FLAC__int32) * wide_samples - 2);
                                else
                                        memcpy(s16buffer, buffer[0], sizeof(FLAC__int32) * wide_samples);
                                for(sample = 0; sample < wide_samples; sample++, buf1_+=2)
                                        *buf1_ = (FLAC__int16)buffer[1][sample];
                                bytes_to_write = 4 * sample;
                        }
                        else if(is_big_endian == is_big_endian_host_ && !is_unsigned_samples && channels == 1 && bps+shift == 16) {
                                FLAC__int16 *buf1_ = s16buffer;
                                for(sample = 0; sample < wide_samples; sample++)
                                        *buf1_++ = (FLAC__int16)buffer[0][sample];
                                bytes_to_write = 2 * sample;
                        }
                        /* generic code for the rest */
                        else if(bps+shift == 16) {
                                if(is_unsigned_samples) {
                                        if(channels == 2) {
                                                for(sample = wide_sample = 0; wide_sample < wide_samples; wide_sample++) {
                                                        u16buffer[sample++] = (FLAC__uint16)(buffer[0][wide_sample] + 0x8000);
                                                        u16buffer[sample++] = (FLAC__uint16)(buffer[1][wide_sample] + 0x8000);
                                                }
                                        }
                                        else if(channels == 1) {
                                                for(sample = wide_sample = 0; wide_sample < wide_samples; wide_sample++)
                                                        u16buffer[sample++] = (FLAC__uint16)(buffer[0][wide_sample] + 0x8000);
                                        }
                                        else { /* works for any 'channels' but above flavors are faster for 1 and 2 */
                                                for(sample = wide_sample = 0; wide_sample < wide_samples; wide_sample++)
                                                        for(channel = 0; channel < channels; channel++, sample++)
                                                                u16buffer[sample] = (FLAC__uint16)(buffer[channel][wide_sample] + 0x8000);
                                        }
                                }
                                else {
                                        if(channels == 2) {
                                                for(sample = wide_sample = 0; wide_sample < wide_samples; wide_sample++) {
                                                        s16buffer[sample++] = (FLAC__int16)(buffer[0][wide_sample]);
                                                        s16buffer[sample++] = (FLAC__int16)(buffer[1][wide_sample]);
                                                }
                                        }
                                        else if(channels == 1) {
                                                for(sample = wide_sample = 0; wide_sample < wide_samples; wide_sample++)
                                                        s16buffer[sample++] = (FLAC__int16)(buffer[0][wide_sample]);
                                        }
                                        else { /* works for any 'channels' but above flavors are faster for 1 and 2 */
                                                for(sample = wide_sample = 0; wide_sample < wide_samples; wide_sample++)
                                                        for(channel = 0; channel < channels; channel++, sample++)
                                                                s16buffer[sample] = (FLAC__int16)(buffer[channel][wide_sample]);
                                        }
                                }
                                if(is_big_endian != is_big_endian_host_) {
                                        unsigned char tmp;
                                        const unsigned bytes = sample * 2;
                                        for(byte = 0; byte < bytes; byte += 2) {
                                                tmp = u8buffer[byte];
                                                u8buffer[byte] = u8buffer[byte+1];
                                                u8buffer[byte+1] = tmp;
                                        }
                                }
                                bytes_to_write = 2 * sample;
                        }
                        else if(bps+shift == 24) {
                                if(is_unsigned_samples) {
                                        for(sample = wide_sample = 0; wide_sample < wide_samples; wide_sample++)
                                                for(channel = 0; channel < channels; channel++, sample++)
                                                        u32buffer[sample] = buffer[channel][wide_sample] + 0x800000;
                                }
                                else {
                                        for(sample = wide_sample = 0; wide_sample < wide_samples; wide_sample++)
                                                for(channel = 0; channel < channels; channel++, sample++)
                                                        s32buffer[sample] = buffer[channel][wide_sample];
                                }
                                if(is_big_endian != is_big_endian_host_) {
                                        unsigned char tmp;
                                        const unsigned bytes = sample * 4;
                                        for(byte = 0; byte < bytes; byte += 4) {
                                                tmp = u8buffer[byte];
                                                u8buffer[byte] = u8buffer[byte+3];
                                                u8buffer[byte+3] = tmp;
                                                tmp = u8buffer[byte+1];
                                                u8buffer[byte+1] = u8buffer[byte+2];
                                                u8buffer[byte+2] = tmp;
                                        }
                                }
                                if(is_big_endian) {
                                        unsigned lbyte;
                                        const unsigned bytes = sample * 4;
                                        for(lbyte = byte = 0; byte < bytes; ) {
                                                byte++;
                                                u8buffer[lbyte++] = u8buffer[byte++];
                                                u8buffer[lbyte++] = u8buffer[byte++];
                                                u8buffer[lbyte++] = u8buffer[byte++];
                                        }
                                }
                                else {
                                        unsigned lbyte;
                                        const unsigned bytes = sample * 4;
                                        for(lbyte = byte = 0; byte < bytes; ) {
                                                u8buffer[lbyte++] = u8buffer[byte++];
                                                u8buffer[lbyte++] = u8buffer[byte++];
                                                u8buffer[lbyte++] = u8buffer[byte++];
                                                byte++;
                                        }
                                }
                                bytes_to_write = 3 * sample;
                        }
                        else if(bps+shift == 8) {
                                if(is_unsigned_samples) {
                                        for(sample = wide_sample = 0; wide_sample < wide_samples; wide_sample++)
                                                for(channel = 0; channel < channels; channel++, sample++)
                                                        u8buffer[sample] = (FLAC__uint8)(buffer[channel][wide_sample] + 0x80);
                                }
                                else {
                                        for(sample = wide_sample = 0; wide_sample < wide_samples; wide_sample++)
                                                for(channel = 0; channel < channels; channel++, sample++)
                                                        s8buffer[sample] = (FLAC__int8)(buffer[channel][wide_sample]);
                                }
                                bytes_to_write = sample;
                        }
                        else {
                                FLAC__ASSERT(0);
                                /* double protection */
                                decoder_session->abort_flag = true;
                                return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
                        }
                }
        }
        if(bytes_to_write > 0) {
                if(flac__utils_fwrite(u8buffer, 1, bytes_to_write, fout) != bytes_to_write) {
                        /* if a pipe closed when writing to stdout, we let it go without an error message */
                        if(errno == EPIPE && decoder_session->fout == stdout)
                                decoder_session->aborting_due_to_until = true;
                        decoder_session->abort_flag = true;
                        return FLAC__STREAM_DECODER_WRITE_STATUS_ABORT;
                }
        }
        return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;
}

void metadata_callback(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data)
{
        DecoderSession *decoder_session = (DecoderSession*)client_data;

        if(decoder_session->analysis_mode)
                FLAC__stream_decoder_get_decode_position(decoder, &decoder_session->decode_position);

        if(metadata->type == FLAC__METADATA_TYPE_STREAMINFO) {
                FLAC__uint64 skip, until;
                decoder_session->got_stream_info = true;
                decoder_session->has_md5sum = memcmp(metadata->data.stream_info.md5sum, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", 16);
                decoder_session->bps = metadata->data.stream_info.bits_per_sample;
                decoder_session->channels = metadata->data.stream_info.channels;
                decoder_session->sample_rate = metadata->data.stream_info.sample_rate;

                flac__utils_canonicalize_skip_until_specification(decoder_session->skip_specification, decoder_session->sample_rate);
                FLAC__ASSERT(decoder_session->skip_specification->value.samples >= 0);
                skip = (FLAC__uint64)decoder_session->skip_specification->value.samples;

                /* remember, metadata->data.stream_info.total_samples can be 0, meaning 'unknown' */
                if(metadata->data.stream_info.total_samples > 0 && skip >= metadata->data.stream_info.total_samples) {
                        flac__utils_printf(stderr, 1, "%s: ERROR trying to --skip more samples than in stream\n", decoder_session->inbasefilename);
                        decoder_session->abort_flag = true;
                        return;
                }
                else if(metadata->data.stream_info.total_samples == 0 && skip > 0) {
                        flac__utils_printf(stderr, 1, "%s: ERROR, can't --skip when FLAC metadata has total sample count of 0\n", decoder_session->inbasefilename);
                        decoder_session->abort_flag = true;
                        return;
                }
                FLAC__ASSERT(skip == 0 || 0 == decoder_session->cue_specification);
                decoder_session->total_samples = metadata->data.stream_info.total_samples - skip;

                /* note that we use metadata->data.stream_info.total_samples instead of decoder_session->total_samples */
                if(!canonicalize_until_specification(decoder_session->until_specification, decoder_session->inbasefilename, decoder_session->sample_rate, skip, metadata->data.stream_info.total_samples)) {
                        decoder_session->abort_flag = true;
                        return;
                }
                FLAC__ASSERT(decoder_session->until_specification->value.samples >= 0);
                until = (FLAC__uint64)decoder_session->until_specification->value.samples;

                if(until > 0) {
                        FLAC__ASSERT(decoder_session->total_samples != 0);
                        FLAC__ASSERT(0 == decoder_session->cue_specification);
                        decoder_session->total_samples -= (metadata->data.stream_info.total_samples - until);
                }

                if(decoder_session->bps < 4 || decoder_session->bps > 24) {
                        flac__utils_printf(stderr, 1, "%s: ERROR: bits per sample is %u, must be 4-24\n", decoder_session->inbasefilename, decoder_session->bps);
                        decoder_session->abort_flag = true;
                        return;
                }
        }
        else if(metadata->type == FLAC__METADATA_TYPE_CUESHEET) {
                /* remember, at this point, decoder_session->total_samples can be 0, meaning 'unknown' */
                if(decoder_session->total_samples == 0) {
                        flac__utils_printf(stderr, 1, "%s: ERROR can't use --cue when FLAC metadata has total sample count of 0\n", decoder_session->inbasefilename);
                        decoder_session->abort_flag = true;
                        return;
                }

                flac__utils_canonicalize_cue_specification(decoder_session->cue_specification, &metadata->data.cue_sheet, decoder_session->total_samples, decoder_session->skip_specification, decoder_session->until_specification);

                FLAC__ASSERT(!decoder_session->skip_specification->is_relative);
                FLAC__ASSERT(decoder_session->skip_specification->value_is_samples);

                FLAC__ASSERT(!decoder_session->until_specification->is_relative);
                FLAC__ASSERT(decoder_session->until_specification->value_is_samples);

                FLAC__ASSERT(decoder_session->skip_specification->value.samples >= 0);
                FLAC__ASSERT(decoder_session->until_specification->value.samples >= 0);
                FLAC__ASSERT((FLAC__uint64)decoder_session->until_specification->value.samples <= decoder_session->total_samples);
                FLAC__ASSERT(decoder_session->skip_specification->value.samples <= decoder_session->until_specification->value.samples);

                decoder_session->total_samples = decoder_session->until_specification->value.samples - decoder_session->skip_specification->value.samples;
        }
        else if(metadata->type == FLAC__METADATA_TYPE_VORBIS_COMMENT) {
                if (decoder_session->replaygain.spec.apply) {
                        double reference, gain, peak;
                        if (!(decoder_session->replaygain.apply = grabbag__replaygain_load_from_vorbiscomment(metadata, decoder_session->replaygain.spec.use_album_gain, /*strict=*/false, &reference, &gain, &peak))) {
                                flac__utils_printf(stderr, 1, "%s: WARNING: can't get %s (or even %s) ReplayGain tags\n", decoder_session->inbasefilename, decoder_session->replaygain.spec.use_album_gain? "album":"track", decoder_session->replaygain.spec.use_album_gain? "track":"album");
                                if(decoder_session->treat_warnings_as_errors) {
                                        decoder_session->abort_flag = true;
                                        return;
                                }
                        }
                        else {
                                const char *ls[] = { "no", "peak", "hard" };
                                const char *ns[] = { "no", "low", "medium", "high" };
                                decoder_session->replaygain.scale = grabbag__replaygain_compute_scale_factor(peak, gain, decoder_session->replaygain.spec.preamp, decoder_session->replaygain.spec.limiter == RGSS_LIMIT__PEAK);
                                FLAC__ASSERT(decoder_session->bps > 0 && decoder_session->bps <= 32);
                                FLAC__replaygain_synthesis__init_dither_context(&decoder_session->replaygain.dither_context, decoder_session->bps, decoder_session->replaygain.spec.noise_shaping);
                                flac__utils_printf(stderr, 1, "%s: INFO: applying %s ReplayGain (gain=%0.2fdB+preamp=%0.1fdB, %s noise shaping, %s limiting) to output\n", decoder_session->inbasefilename, decoder_session->replaygain.spec.use_album_gain? "album":"track", gain, decoder_session->replaygain.spec.preamp, ns[decoder_session->replaygain.spec.noise_shaping], ls[decoder_session->replaygain.spec.limiter]);
                                flac__utils_printf(stderr, 1, "%s: WARNING: applying ReplayGain is not lossless\n", decoder_session->inbasefilename);
                                /* don't check if(decoder_session->treat_warnings_as_errors) because the user explicitly asked for it */
                        }
                }
                (void)flac__utils_get_channel_mask_tag(metadata, &decoder_session->channel_mask);
        }
}

void error_callback(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
{
        DecoderSession *decoder_session = (DecoderSession*)client_data;
        (void)decoder;
        flac__utils_printf(stderr, 1, "%s: *** Got error code %d:%s\n", decoder_session->inbasefilename, status, FLAC__StreamDecoderErrorStatusString[status]);
        if(!decoder_session->continue_through_decode_errors) {
                decoder_session->abort_flag = true;
                if(status == FLAC__STREAM_DECODER_ERROR_STATUS_UNPARSEABLE_STREAM)
                        decoder_session->aborting_due_to_unparseable = true;
        }
}

void print_error_with_init_status(const DecoderSession *d, const char *message, FLAC__StreamDecoderInitStatus init_status)
{
        const int ilen = strlen(d->inbasefilename) + 1;

        flac__utils_printf(stderr, 1, "\n%s: %s\n", d->inbasefilename, message);

        flac__utils_printf(stderr, 1, "%*s init status = %s\n", ilen, "", FLAC__StreamDecoderInitStatusString[init_status]);

        /* print out some more info for some errors: */
        if (init_status == FLAC__STREAM_DECODER_INIT_STATUS_ERROR_OPENING_FILE) {
                flac__utils_printf(stderr, 1,
                        "\n"
                        "An error occurred opening the input file; it is likely that it does not exist\n"
                        "or is not readable.\n"
                );
        }
}

void print_error_with_state(const DecoderSession *d, const char *message)
{
        const int ilen = strlen(d->inbasefilename) + 1;

        flac__utils_printf(stderr, 1, "\n%s: %s\n", d->inbasefilename, message);
        flac__utils_printf(stderr, 1, "%*s state = %s\n", ilen, "", FLAC__stream_decoder_get_resolved_state_string(d->decoder));

        /* print out some more info for some errors: */
        if (d->aborting_due_to_unparseable) {
                flac__utils_printf(stderr, 1,
                        "\n"
                        "The FLAC stream may have been created by a more advanced encoder.  Try\n"
                        "  metaflac --show-vendor-tag %s\n"
                        "If the version number is greater than %s, this decoder is probably\n"
                        "not able to decode the file.  If the version number is not, the file\n"
                        "may be corrupted, or you may have found a bug.  In this case please\n"
                        "submit a bug report to\n"
                        "    http://sourceforge.net/bugs/?func=addbug&group_id=13478\n"
                        "Make sure to use the \"Monitor\" feature to monitor the bug status.\n",
                        d->inbasefilename, FLAC__VERSION_STRING
                );
        }
}

void print_stats(const DecoderSession *decoder_session)
{
        if(flac__utils_verbosity_ >= 2) {
#if defined _MSC_VER || defined __MINGW32__
                /* with MSVC you have to spoon feed it the casting */
                const double progress = (double)(FLAC__int64)decoder_session->samples_processed / (double)(FLAC__int64)decoder_session->total_samples * 100.0;
#else
                const double progress = (double)decoder_session->samples_processed / (double)decoder_session->total_samples * 100.0;
#endif
                if(decoder_session->total_samples > 0) {
                        fprintf(stderr, "\r%s: %s%u%% complete",
                                decoder_session->inbasefilename,
                                decoder_session->test_only? "testing, " : decoder_session->analysis_mode? "analyzing, " : "",
                                (unsigned)floor(progress + 0.5)
                        );
                }
                else {
                        fprintf(stderr, "\r%s: %s %u samples",
                                decoder_session->inbasefilename,
                                decoder_session->test_only? "tested" : decoder_session->analysis_mode? "analyzed" : "wrote",
                                (unsigned)decoder_session->samples_processed
                        );
                }
        }
}