libavformat/westwood.c

   1 /*
   2  * Westwood Studios Multimedia Formats Demuxer (VQA, AUD)
   3  * Copyright (c) 2003 The ffmpeg Project
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file libavformat/westwood.c
  24  * Westwood Studios VQA & AUD file demuxers
  25  * by Mike Melanson (melanson@pcisys.net)
  26  * for more information on the Westwood file formats, visit:
  27  *   http://www.pcisys.net/~melanson/codecs/
  28  *   http://www.geocities.com/SiliconValley/8682/aud3.txt
  29  *
  30  * Implementation note: There is no definite file signature for AUD files.
  31  * The demuxer uses a probabilistic strategy for content detection. This
  32  * entails performing sanity checks on certain header values in order to
  33  * qualify a file. Refer to wsaud_probe() for the precise parameters.
  34  */
  35
  36 #include "libavutil/intreadwrite.h"
  37 #include "avformat.h"
  38
  39 #define AUD_HEADER_SIZE 12
  40 #define AUD_CHUNK_PREAMBLE_SIZE 8
  41 #define AUD_CHUNK_SIGNATURE 0x0000DEAF
  42
  43 #define FORM_TAG MKBETAG('F', 'O', 'R', 'M')
  44 #define WVQA_TAG MKBETAG('W', 'V', 'Q', 'A')
  45 #define VQHD_TAG MKBETAG('V', 'Q', 'H', 'D')
  46 #define FINF_TAG MKBETAG('F', 'I', 'N', 'F')
  47 #define SND0_TAG MKBETAG('S', 'N', 'D', '0')
  48 #define SND1_TAG MKBETAG('S', 'N', 'D', '1')
  49 #define SND2_TAG MKBETAG('S', 'N', 'D', '2')
  50 #define VQFR_TAG MKBETAG('V', 'Q', 'F', 'R')
  51
  52 /* don't know what these tags are for, but acknowledge their existence */
  53 #define CINF_TAG MKBETAG('C', 'I', 'N', 'F')
  54 #define CINH_TAG MKBETAG('C', 'I', 'N', 'H')
  55 #define CIND_TAG MKBETAG('C', 'I', 'N', 'D')
  56 #define PINF_TAG MKBETAG('P', 'I', 'N', 'F')
  57 #define PINH_TAG MKBETAG('P', 'I', 'N', 'H')
  58 #define PIND_TAG MKBETAG('P', 'I', 'N', 'D')
  59 #define CMDS_TAG MKBETAG('C', 'M', 'D', 'S')
  60
  61 #define VQA_HEADER_SIZE 0x2A
  62 #define VQA_FRAMERATE 15
  63 #define VQA_PREAMBLE_SIZE 8
  64
  65 typedef struct WsAudDemuxContext {
  66     int audio_samplerate;
  67     int audio_channels;
  68     int audio_bits;
  69     enum CodecID audio_type;
  70     int audio_stream_index;
  71     int64_t audio_frame_counter;
  72 } WsAudDemuxContext;
  73
  74 typedef struct WsVqaDemuxContext {
  75     int audio_samplerate;
  76     int audio_channels;
  77     int audio_bits;
  78
  79     int audio_stream_index;
  80     int video_stream_index;
  81
  82     int64_t audio_frame_counter;
  83 } WsVqaDemuxContext;
  84
  85 static int wsaud_probe(AVProbeData *p)
  86 {
  87     int field;
  88
  89     /* Probabilistic content detection strategy: There is no file signature
  90      * so perform sanity checks on various header parameters:
  91      *   8000 <= sample rate (16 bits) <= 48000  ==> 40001 acceptable numbers
  92      *   flags <= 0x03 (2 LSBs are used)         ==> 4 acceptable numbers
  93      *   compression type (8 bits) = 1 or 99     ==> 2 acceptable numbers
  94      *   first audio chunk signature (32 bits)   ==> 1 acceptable number
  95      * The number space contains 2^64 numbers. There are 40001 * 4 * 2 * 1 =
  96      * 320008 acceptable number combinations.
  97      */
  98
  99     if (p->buf_size < AUD_HEADER_SIZE + AUD_CHUNK_PREAMBLE_SIZE)
 100         return 0;
 101
 102     /* check sample rate */
 103     field = AV_RL16(&p->buf[0]);
 104     if ((field < 8000) || (field > 48000))
 105         return 0;
 106
 107     /* enforce the rule that the top 6 bits of this flags field are reserved (0);
 108      * this might not be true, but enforce it until deemed unnecessary */
 109     if (p->buf[10] & 0xFC)
 110         return 0;
 111
 112     /* note: only check for WS IMA (type 99) right now since there is no
 113      * support for type 1 */
 114     if (p->buf[11] != 99)
 115         return 0;
 116
 117     /* read ahead to the first audio chunk and validate the first header signature */
 118     if (AV_RL32(&p->buf[16]) != AUD_CHUNK_SIGNATURE)
 119         return 0;
 120
 121     /* return 1/2 certainty since this file check is a little sketchy */
 122     return AVPROBE_SCORE_MAX / 2;
 123 }
 124
 125 static int wsaud_read_header(AVFormatContext *s,
 126                              AVFormatParameters *ap)
 127 {
 128     WsAudDemuxContext *wsaud = s->priv_data;
 129     ByteIOContext *pb = s->pb;
 130     AVStream *st;
 131     unsigned char header[AUD_HEADER_SIZE];
 132
 133     if (get_buffer(pb, header, AUD_HEADER_SIZE) != AUD_HEADER_SIZE)
 134         return AVERROR(EIO);
 135     wsaud->audio_samplerate = AV_RL16(&header[0]);
 136     if (header[11] == 99)
 137         wsaud->audio_type = CODEC_ID_ADPCM_IMA_WS;
 138     else
 139         return AVERROR_INVALIDDATA;
 140
 141     /* flag 0 indicates stereo */
 142     wsaud->audio_channels = (header[10] & 0x1) + 1;
 143     /* flag 1 indicates 16 bit audio */
 144     wsaud->audio_bits = (((header[10] & 0x2) >> 1) + 1) * 8;
 145
 146     /* initialize the audio decoder stream */
 147     st = av_new_stream(s, 0);
 148     if (!st)
 149         return AVERROR(ENOMEM);
 150     av_set_pts_info(st, 33, 1, wsaud->audio_samplerate);
 151     st->codec->codec_type = CODEC_TYPE_AUDIO;
 152     st->codec->codec_id = wsaud->audio_type;
 153     st->codec->codec_tag = 0;  /* no tag */
 154     st->codec->channels = wsaud->audio_channels;
 155     st->codec->sample_rate = wsaud->audio_samplerate;
 156     st->codec->bits_per_coded_sample = wsaud->audio_bits;
 157     st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
 158         st->codec->bits_per_coded_sample / 4;
 159     st->codec->block_align = st->codec->channels * st->codec->bits_per_coded_sample;
 160
 161     wsaud->audio_stream_index = st->index;
 162     wsaud->audio_frame_counter = 0;
 163
 164     return 0;
 165 }
 166
 167 static int wsaud_read_packet(AVFormatContext *s,
 168                              AVPacket *pkt)
 169 {
 170     WsAudDemuxContext *wsaud = s->priv_data;
 171     ByteIOContext *pb = s->pb;
 172     unsigned char preamble[AUD_CHUNK_PREAMBLE_SIZE];
 173     unsigned int chunk_size;
 174     int ret = 0;
 175
 176     if (get_buffer(pb, preamble, AUD_CHUNK_PREAMBLE_SIZE) !=
 177         AUD_CHUNK_PREAMBLE_SIZE)
 178         return AVERROR(EIO);
 179
 180     /* validate the chunk */
 181     if (AV_RL32(&preamble[4]) != AUD_CHUNK_SIGNATURE)
 182         return AVERROR_INVALIDDATA;
 183
 184     chunk_size = AV_RL16(&preamble[0]);
 185     ret= av_get_packet(pb, pkt, chunk_size);
 186     if (ret != chunk_size)
 187         return AVERROR(EIO);
 188     pkt->stream_index = wsaud->audio_stream_index;
 189     pkt->pts = wsaud->audio_frame_counter;
 190     pkt->pts /= wsaud->audio_samplerate;
 191
 192     /* 2 samples/byte, 1 or 2 samples per frame depending on stereo */
 193     wsaud->audio_frame_counter += (chunk_size * 2) / wsaud->audio_channels;
 194
 195     return ret;
 196 }
 197
 198 static int wsvqa_probe(AVProbeData *p)
 199 {
 200     /* need 12 bytes to qualify */
 201     if (p->buf_size < 12)
 202         return 0;
 203
 204     /* check for the VQA signatures */
 205     if ((AV_RB32(&p->buf[0]) != FORM_TAG) ||
 206         (AV_RB32(&p->buf[8]) != WVQA_TAG))
 207         return 0;
 208
 209     return AVPROBE_SCORE_MAX;
 210 }
 211
 212 static int wsvqa_read_header(AVFormatContext *s,
 213                              AVFormatParameters *ap)
 214 {
 215     WsVqaDemuxContext *wsvqa = s->priv_data;
 216     ByteIOContext *pb = s->pb;
 217     AVStream *st;
 218     unsigned char *header;
 219     unsigned char scratch[VQA_PREAMBLE_SIZE];
 220     unsigned int chunk_tag;
 221     unsigned int chunk_size;
 222
 223     /* initialize the video decoder stream */
 224     st = av_new_stream(s, 0);
 225     if (!st)
 226         return AVERROR(ENOMEM);
 227     av_set_pts_info(st, 33, 1, VQA_FRAMERATE);
 228     wsvqa->video_stream_index = st->index;
 229     st->codec->codec_type = CODEC_TYPE_VIDEO;
 230     st->codec->codec_id = CODEC_ID_WS_VQA;
 231     st->codec->codec_tag = 0;  /* no fourcc */
 232
 233     /* skip to the start of the VQA header */
 234     url_fseek(pb, 20, SEEK_SET);
 235
 236     /* the VQA header needs to go to the decoder */
 237     st->codec->extradata_size = VQA_HEADER_SIZE;
 238     st->codec->extradata = av_mallocz(VQA_HEADER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
 239     header = (unsigned char *)st->codec->extradata;
 240     if (get_buffer(pb, st->codec->extradata, VQA_HEADER_SIZE) !=
 241         VQA_HEADER_SIZE) {
 242         av_free(st->codec->extradata);
 243         return AVERROR(EIO);
 244     }
 245     st->codec->width = AV_RL16(&header[6]);
 246     st->codec->height = AV_RL16(&header[8]);
 247
 248     /* initialize the audio decoder stream for VQA v1 or nonzero samplerate */
 249     if (AV_RL16(&header[24]) || (AV_RL16(&header[0]) == 1 && AV_RL16(&header[2]) == 1)) {
 250         st = av_new_stream(s, 0);
 251         if (!st)
 252             return AVERROR(ENOMEM);
 253         av_set_pts_info(st, 33, 1, VQA_FRAMERATE);
 254         st->codec->codec_type = CODEC_TYPE_AUDIO;
 255         if (AV_RL16(&header[0]) == 1)
 256             st->codec->codec_id = CODEC_ID_WESTWOOD_SND1;
 257         else
 258             st->codec->codec_id = CODEC_ID_ADPCM_IMA_WS;
 259         st->codec->codec_tag = 0;  /* no tag */
 260         st->codec->sample_rate = AV_RL16(&header[24]);
 261         if (!st->codec->sample_rate)
 262             st->codec->sample_rate = 22050;
 263         st->codec->channels = header[26];
 264         if (!st->codec->channels)
 265             st->codec->channels = 1;
 266         st->codec->bits_per_coded_sample = 16;
 267         st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
 268             st->codec->bits_per_coded_sample / 4;
 269         st->codec->block_align = st->codec->channels * st->codec->bits_per_coded_sample;
 270
 271         wsvqa->audio_stream_index = st->index;
 272         wsvqa->audio_samplerate = st->codec->sample_rate;
 273         wsvqa->audio_channels = st->codec->channels;
 274         wsvqa->audio_frame_counter = 0;
 275     }
 276
 277     /* there are 0 or more chunks before the FINF chunk; iterate until
 278      * FINF has been skipped and the file will be ready to be demuxed */
 279     do {
 280         if (get_buffer(pb, scratch, VQA_PREAMBLE_SIZE) != VQA_PREAMBLE_SIZE) {
 281             av_free(st->codec->extradata);
 282             return AVERROR(EIO);
 283         }
 284         chunk_tag = AV_RB32(&scratch[0]);
 285         chunk_size = AV_RB32(&scratch[4]);
 286
 287         /* catch any unknown header tags, for curiousity */
 288         switch (chunk_tag) {
 289         case CINF_TAG:
 290         case CINH_TAG:
 291         case CIND_TAG:
 292         case PINF_TAG:
 293         case PINH_TAG:
 294         case PIND_TAG:
 295         case FINF_TAG:
 296         case CMDS_TAG:
 297             break;
 298
 299         default:
 300             av_log (s, AV_LOG_ERROR, " note: unknown chunk seen (%c%c%c%c)\n",
 301                 scratch[0], scratch[1],
 302                 scratch[2], scratch[3]);
 303             break;
 304         }
 305
 306         url_fseek(pb, chunk_size, SEEK_CUR);
 307     } while (chunk_tag != FINF_TAG);
 308
 309     return 0;
 310 }
 311
 312 static int wsvqa_read_packet(AVFormatContext *s,
 313                              AVPacket *pkt)
 314 {
 315     WsVqaDemuxContext *wsvqa = s->priv_data;
 316     ByteIOContext *pb = s->pb;
 317     int ret = -1;
 318     unsigned char preamble[VQA_PREAMBLE_SIZE];
 319     unsigned int chunk_type;
 320     unsigned int chunk_size;
 321     int skip_byte;
 322
 323     while (get_buffer(pb, preamble, VQA_PREAMBLE_SIZE) == VQA_PREAMBLE_SIZE) {
 324         chunk_type = AV_RB32(&preamble[0]);
 325         chunk_size = AV_RB32(&preamble[4]);
 326         skip_byte = chunk_size & 0x01;
 327
 328         if ((chunk_type == SND1_TAG) || (chunk_type == SND2_TAG) || (chunk_type == VQFR_TAG)) {
 329
 330             if (av_new_packet(pkt, chunk_size))
 331                 return AVERROR(EIO);
 332             ret = get_buffer(pb, pkt->data, chunk_size);
 333             if (ret != chunk_size) {
 334                 av_free_packet(pkt);
 335                 return AVERROR(EIO);
 336             }
 337
 338             if (chunk_type == SND2_TAG) {
 339                 pkt->stream_index = wsvqa->audio_stream_index;
 340                 /* 2 samples/byte, 1 or 2 samples per frame depending on stereo */
 341                 wsvqa->audio_frame_counter += (chunk_size * 2) / wsvqa->audio_channels;
 342             } else if(chunk_type == SND1_TAG) {
 343                 pkt->stream_index = wsvqa->audio_stream_index;
 344                 /* unpacked size is stored in header */
 345                 wsvqa->audio_frame_counter += AV_RL16(pkt->data) / wsvqa->audio_channels;
 346             } else {
 347                 pkt->stream_index = wsvqa->video_stream_index;
 348             }
 349             /* stay on 16-bit alignment */
 350             if (skip_byte)
 351                 url_fseek(pb, 1, SEEK_CUR);
 352
 353             return ret;
 354         } else {
 355             switch(chunk_type){
 356             case CMDS_TAG:
 357             case SND0_TAG:
 358                 break;
 359             default:
 360                 av_log(s, AV_LOG_INFO, "Skipping unknown chunk 0x%08X\n", chunk_type);
 361             }
 362             url_fseek(pb, chunk_size + skip_byte, SEEK_CUR);
 363         }
 364     }
 365
 366     return ret;
 367 }
 368
 369 #if CONFIG_WSAUD_DEMUXER
 370 AVInputFormat wsaud_demuxer = {
 371     "wsaud",
 372     NULL_IF_CONFIG_SMALL("Westwood Studios audio format"),
 373     sizeof(WsAudDemuxContext),
 374     wsaud_probe,
 375     wsaud_read_header,
 376     wsaud_read_packet,
 377 };
 378 #endif
 379 #if CONFIG_WSVQA_DEMUXER
 380 AVInputFormat wsvqa_demuxer = {
 381     "wsvqa",
 382     NULL_IF_CONFIG_SMALL("Westwood Studios VQA format"),
 383     sizeof(WsVqaDemuxContext),
 384     wsvqa_probe,
 385     wsvqa_read_header,
 386     wsvqa_read_packet,
 387 };
 388 #endif