libavcodec/nellymoserdec.c

   1 /*
   2  * NellyMoser audio decoder
   3  * Copyright (c) 2007 a840bda5870ba11f19698ff6eb9581dfb0f95fa5,
   4  *                    539459aeb7d425140b62a3ec7dbf6dc8e408a306, and
   5  *                    520e17cd55896441042b14df2566a6eb610ed444
   6  * Copyright (c) 2007 Loic Minier <lool at dooz.org>
   7  *                    Benjamin Larsson
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included in
  17  * all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  22  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  23  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  24  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  25  * DEALINGS IN THE SOFTWARE.
  26  */
  27
  28 /**
  29  * @file
  30  * The 3 alphanumeric copyright notices are md5summed they are from the original
  31  * implementors. The original code is available from http://code.google.com/p/nelly2pcm/
  32  */
  33
  34 #include "libavutil/channel_layout.h"
  35 #include "libavutil/float_dsp.h"
  36 #include "libavutil/lfg.h"
  37 #include "libavutil/random_seed.h"
  38 #include "avcodec.h"
  39 #include "dsputil.h"
  40 #include "fft.h"
  41 #include "fmtconvert.h"
  42 #include "internal.h"
  43 #include "nellymoser.h"
  44 #include "sinewin.h"
  45
  46 #define BITSTREAM_READER_LE
  47 #include "get_bits.h"
  48
  49
  50 typedef struct NellyMoserDecodeContext {
  51     AVCodecContext* avctx;
  52     AVFrame         frame;
  53     AVLFG           random_state;
  54     GetBitContext   gb;
  55     float           scale_bias;
  56     AVFloatDSPContext fdsp;
  57     FFTContext      imdct_ctx;
  58     DECLARE_ALIGNED(32, float, imdct_buf)[2][NELLY_BUF_LEN];
  59     float          *imdct_out;
  60     float          *imdct_prev;
  61 } NellyMoserDecodeContext;
  62
  63 static void nelly_decode_block(NellyMoserDecodeContext *s,
  64                                const unsigned char block[NELLY_BLOCK_LEN],
  65                                float audio[NELLY_SAMPLES])
  66 {
  67     int i,j;
  68     float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN];
  69     float *aptr, *bptr, *pptr, val, pval;
  70     int bits[NELLY_BUF_LEN];
  71     unsigned char v;
  72
  73     init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
  74
  75     bptr = buf;
  76     pptr = pows;
  77     val = ff_nelly_init_table[get_bits(&s->gb, 6)];
  78     for (i=0 ; i<NELLY_BANDS ; i++) {
  79         if (i > 0)
  80             val += ff_nelly_delta_table[get_bits(&s->gb, 5)];
  81         pval = -pow(2, val/2048) * s->scale_bias;
  82         for (j = 0; j < ff_nelly_band_sizes_table[i]; j++) {
  83             *bptr++ = val;
  84             *pptr++ = pval;
  85         }
  86
  87     }
  88
  89     ff_nelly_get_sample_bits(buf, bits);
  90
  91     for (i = 0; i < 2; i++) {
  92         aptr = audio + i * NELLY_BUF_LEN;
  93
  94         init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
  95         skip_bits_long(&s->gb, NELLY_HEADER_BITS + i*NELLY_DETAIL_BITS);
  96
  97         for (j = 0; j < NELLY_FILL_LEN; j++) {
  98             if (bits[j] <= 0) {
  99                 aptr[j] = M_SQRT1_2*pows[j];
 100                 if (av_lfg_get(&s->random_state) & 1)
 101                     aptr[j] *= -1.0;
 102             } else {
 103                 v = get_bits(&s->gb, bits[j]);
 104                 aptr[j] = ff_nelly_dequantization_table[(1<<bits[j])-1+v]*pows[j];
 105             }
 106         }
 107         memset(&aptr[NELLY_FILL_LEN], 0,
 108                (NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));
 109
 110         s->imdct_ctx.imdct_half(&s->imdct_ctx, s->imdct_out, aptr);
 111         s->fdsp.vector_fmul_window(aptr, s->imdct_prev + NELLY_BUF_LEN / 2,
 112                                    s->imdct_out, ff_sine_128,
 113                                    NELLY_BUF_LEN / 2);
 114         FFSWAP(float *, s->imdct_out, s->imdct_prev);
 115     }
 116 }
 117
 118 static av_cold int decode_init(AVCodecContext * avctx) {
 119     NellyMoserDecodeContext *s = avctx->priv_data;
 120
 121     s->avctx = avctx;
 122     s->imdct_out = s->imdct_buf[0];
 123     s->imdct_prev = s->imdct_buf[1];
 124     av_lfg_init(&s->random_state, 0);
 125     ff_mdct_init(&s->imdct_ctx, 8, 1, 1.0);
 126
 127     avpriv_float_dsp_init(&s->fdsp, avctx->flags & CODEC_FLAG_BITEXACT);
 128
 129     s->scale_bias = 1.0/(32768*8);
 130     avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
 131
 132     /* Generate overlap window */
 133     if (!ff_sine_128[127])
 134         ff_init_ff_sine_windows(7);
 135
 136     avctx->channels       = 1;
 137     avctx->channel_layout = AV_CH_LAYOUT_MONO;
 138
 139     avcodec_get_frame_defaults(&s->frame);
 140     avctx->coded_frame = &s->frame;
 141
 142     return 0;
 143 }
 144
 145 static int decode_tag(AVCodecContext *avctx, void *data,
 146                       int *got_frame_ptr, AVPacket *avpkt)
 147 {
 148     const uint8_t *buf = avpkt->data;
 149     int buf_size = avpkt->size;
 150     NellyMoserDecodeContext *s = avctx->priv_data;
 151     int blocks, i, ret;
 152     float   *samples_flt;
 153
 154     blocks     = buf_size / NELLY_BLOCK_LEN;
 155     if (blocks <= 0) {
 156         av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
 157         return AVERROR_INVALIDDATA;
 158     }
 159     if (buf_size % NELLY_BLOCK_LEN) {
 160         av_log(avctx, AV_LOG_WARNING, "Leftover bytes: %d.\n",
 161                buf_size % NELLY_BLOCK_LEN);
 162     }
 163     /* Normal numbers of blocks for sample rates:
 164      *  8000 Hz - 1
 165      * 11025 Hz - 2
 166      * 16000 Hz - 3
 167      * 22050 Hz - 4
 168      * 44100 Hz - 8
 169      */
 170
 171     /* get output buffer */
 172     s->frame.nb_samples = NELLY_SAMPLES * blocks;
 173     if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {
 174         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 175         return ret;
 176     }
 177     samples_flt = (float   *)s->frame.data[0];
 178
 179     for (i=0 ; i<blocks ; i++) {
 180         nelly_decode_block(s, buf, samples_flt);
 181         samples_flt += NELLY_SAMPLES;
 182         buf += NELLY_BLOCK_LEN;
 183     }
 184
 185     *got_frame_ptr   = 1;
 186     *(AVFrame *)data = s->frame;
 187
 188     return buf_size;
 189 }
 190
 191 static av_cold int decode_end(AVCodecContext * avctx) {
 192     NellyMoserDecodeContext *s = avctx->priv_data;
 193
 194     ff_mdct_end(&s->imdct_ctx);
 195
 196     return 0;
 197 }
 198
 199 AVCodec ff_nellymoser_decoder = {
 200     .name           = "nellymoser",
 201     .type           = AVMEDIA_TYPE_AUDIO,
 202     .id             = AV_CODEC_ID_NELLYMOSER,
 203     .priv_data_size = sizeof(NellyMoserDecodeContext),
 204     .init           = decode_init,
 205     .close          = decode_end,
 206     .decode         = decode_tag,
 207     .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_PARAM_CHANGE,
 208     .long_name      = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
 209     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
 210                                                       AV_SAMPLE_FMT_NONE },
 211 };