libavcodec/pcm-mpeg.c

   1 /*
   2  * LPCM codecs for PCM formats found in MPEG streams
   3  * Copyright (c) 2009 Christian Schmidt
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; 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
  24  * PCM codecs for encodings found in MPEG streams (DVD/Blu-ray)
  25  */
  26
  27 #include "libavutil/channel_layout.h"
  28 #include "avcodec.h"
  29 #include "bytestream.h"
  30
  31 /*
  32  * Channel Mapping according to
  33  * Blu-ray Disc Read-Only Format Version 1
  34  * Part 3: Audio Visual Basic Specifications
  35  * mono     M1    X
  36  * stereo   L     R
  37  * 3/0      L     R    C    X
  38  * 2/1      L     R    S    X
  39  * 3/1      L     R    C    S
  40  * 2/2      L     R    LS   RS
  41  * 3/2      L     R    C    LS    RS    X
  42  * 3/2+lfe  L     R    C    LS    RS    lfe
  43  * 3/4      L     R    C    LS    Rls   Rrs  RS   X
  44  * 3/4+lfe  L     R    C    LS    Rls   Rrs  RS   lfe
  45  */
  46
  47 /**
  48  * Parse the header of a LPCM frame read from a MPEG-TS stream
  49  * @param avctx the codec context
  50  * @param header pointer to the first four bytes of the data packet
  51  */
  52 static int pcm_bluray_parse_header(AVCodecContext *avctx,
  53                                    const uint8_t *header)
  54 {
  55     static const uint8_t bits_per_samples[4] = { 0, 16, 20, 24 };
  56     static const uint32_t channel_layouts[16] = {
  57         0, AV_CH_LAYOUT_MONO, 0, AV_CH_LAYOUT_STEREO, AV_CH_LAYOUT_SURROUND,
  58         AV_CH_LAYOUT_2_1, AV_CH_LAYOUT_4POINT0, AV_CH_LAYOUT_2_2, AV_CH_LAYOUT_5POINT0,
  59         AV_CH_LAYOUT_5POINT1, AV_CH_LAYOUT_7POINT0, AV_CH_LAYOUT_7POINT1, 0, 0, 0, 0
  60     };
  61     static const uint8_t channels[16] = {
  62         0, 1, 0, 2, 3, 3, 4, 4, 5, 6, 7, 8, 0, 0, 0, 0
  63     };
  64     uint8_t channel_layout = header[2] >> 4;
  65
  66     if (avctx->debug & FF_DEBUG_PICT_INFO)
  67         av_dlog(avctx, "pcm_bluray_parse_header: header = %02x%02x%02x%02x\n",
  68                 header[0], header[1], header[2], header[3]);
  69
  70     /* get the sample depth and derive the sample format from it */
  71     avctx->bits_per_coded_sample = bits_per_samples[header[3] >> 6];
  72     if (!avctx->bits_per_coded_sample) {
  73         av_log(avctx, AV_LOG_ERROR, "reserved sample depth (0)\n");
  74         return -1;
  75     }
  76     avctx->sample_fmt = avctx->bits_per_coded_sample == 16 ? AV_SAMPLE_FMT_S16 :
  77                                                              AV_SAMPLE_FMT_S32;
  78     avctx->bits_per_raw_sample = avctx->bits_per_coded_sample;
  79
  80     /* get the sample rate. Not all values are used. */
  81     switch (header[2] & 0x0f) {
  82     case 1:
  83         avctx->sample_rate = 48000;
  84         break;
  85     case 4:
  86         avctx->sample_rate = 96000;
  87         break;
  88     case 5:
  89         avctx->sample_rate = 192000;
  90         break;
  91     default:
  92         avctx->sample_rate = 0;
  93         av_log(avctx, AV_LOG_ERROR, "reserved sample rate (%d)\n",
  94                header[2] & 0x0f);
  95         return -1;
  96     }
  97
  98     /*
  99      * get the channel number (and mapping). Not all values are used.
 100      * It must be noted that the number of channels in the MPEG stream can
 101      * differ from the actual meaningful number, e.g. mono audio still has two
 102      * channels, one being empty.
 103      */
 104     avctx->channel_layout  = channel_layouts[channel_layout];
 105     avctx->channels        =        channels[channel_layout];
 106     if (!avctx->channels) {
 107         av_log(avctx, AV_LOG_ERROR, "reserved channel configuration (%d)\n",
 108                channel_layout);
 109         return -1;
 110     }
 111
 112     avctx->bit_rate = FFALIGN(avctx->channels, 2) * avctx->sample_rate *
 113                       avctx->bits_per_coded_sample;
 114
 115     if (avctx->debug & FF_DEBUG_PICT_INFO)
 116         av_dlog(avctx,
 117                 "pcm_bluray_parse_header: %d channels, %d bits per sample, %d Hz, %d bit/s\n",
 118                 avctx->channels, avctx->bits_per_coded_sample,
 119                 avctx->sample_rate, avctx->bit_rate);
 120     return 0;
 121 }
 122
 123 typedef struct PCMBRDecode {
 124     AVFrame frame;
 125 } PCMBRDecode;
 126
 127 static av_cold int pcm_bluray_decode_init(AVCodecContext * avctx)
 128 {
 129     PCMBRDecode *s = avctx->priv_data;
 130
 131     avcodec_get_frame_defaults(&s->frame);
 132     avctx->coded_frame = &s->frame;
 133
 134     return 0;
 135 }
 136
 137 static int pcm_bluray_decode_frame(AVCodecContext *avctx, void *data,
 138                                    int *got_frame_ptr, AVPacket *avpkt)
 139 {
 140     const uint8_t *src = avpkt->data;
 141     int buf_size = avpkt->size;
 142     PCMBRDecode *s = avctx->priv_data;
 143     GetByteContext gb;
 144     int num_source_channels, channel, retval;
 145     int sample_size, samples;
 146     int16_t *dst16;
 147     int32_t *dst32;
 148
 149     if (buf_size < 4) {
 150         av_log(avctx, AV_LOG_ERROR, "PCM packet too small\n");
 151         return -1;
 152     }
 153
 154     if (pcm_bluray_parse_header(avctx, src))
 155         return -1;
 156     src += 4;
 157     buf_size -= 4;
 158
 159     bytestream2_init(&gb, src, buf_size);
 160
 161     /* There's always an even number of channels in the source */
 162     num_source_channels = FFALIGN(avctx->channels, 2);
 163     sample_size = (num_source_channels * (avctx->sample_fmt == AV_SAMPLE_FMT_S16 ? 16 : 24)) >> 3;
 164     samples = buf_size / sample_size;
 165
 166     /* get output buffer */
 167     s->frame.nb_samples = samples;
 168     if ((retval = avctx->get_buffer(avctx, &s->frame)) < 0) {
 169         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 170         return retval;
 171     }
 172     dst16 = (int16_t *)s->frame.data[0];
 173     dst32 = (int32_t *)s->frame.data[0];
 174
 175     if (samples) {
 176         switch (avctx->channel_layout) {
 177             /* cases with same number of source and coded channels */
 178         case AV_CH_LAYOUT_STEREO:
 179         case AV_CH_LAYOUT_4POINT0:
 180         case AV_CH_LAYOUT_2_2:
 181             samples *= num_source_channels;
 182             if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
 183 #if HAVE_BIGENDIAN
 184                 bytestream2_get_buffer(&gb, dst16, buf_size);
 185 #else
 186                 do {
 187                     *dst16++ = bytestream2_get_be16u(&gb);
 188                 } while (--samples);
 189 #endif
 190             } else {
 191                 do {
 192                     *dst32++ = bytestream2_get_be24u(&gb) << 8;
 193                 } while (--samples);
 194             }
 195             break;
 196         /* cases where number of source channels = coded channels + 1 */
 197         case AV_CH_LAYOUT_MONO:
 198         case AV_CH_LAYOUT_SURROUND:
 199         case AV_CH_LAYOUT_2_1:
 200         case AV_CH_LAYOUT_5POINT0:
 201             if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
 202                 do {
 203 #if HAVE_BIGENDIAN
 204                     bytestream2_get_buffer(&gb, dst16, avctx->channels * 2);
 205                     dst16 += avctx->channels;
 206 #else
 207                     channel = avctx->channels;
 208                     do {
 209                         *dst16++ = bytestream2_get_be16u(&gb);
 210                     } while (--channel);
 211 #endif
 212                     bytestream2_skip(&gb, 2);
 213                 } while (--samples);
 214             } else {
 215                 do {
 216                     channel = avctx->channels;
 217                     do {
 218                         *dst32++ = bytestream2_get_be24u(&gb) << 8;
 219                     } while (--channel);
 220                     bytestream2_skip(&gb, 3);
 221                 } while (--samples);
 222             }
 223             break;
 224             /* remapping: L, R, C, LBack, RBack, LF */
 225         case AV_CH_LAYOUT_5POINT1:
 226             if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
 227                 do {
 228                     dst16[0] = bytestream2_get_be16u(&gb);
 229                     dst16[1] = bytestream2_get_be16u(&gb);
 230                     dst16[2] = bytestream2_get_be16u(&gb);
 231                     dst16[4] = bytestream2_get_be16u(&gb);
 232                     dst16[5] = bytestream2_get_be16u(&gb);
 233                     dst16[3] = bytestream2_get_be16u(&gb);
 234                     dst16 += 6;
 235                 } while (--samples);
 236             } else {
 237                 do {
 238                     dst32[0] = bytestream2_get_be24u(&gb) << 8;
 239                     dst32[1] = bytestream2_get_be24u(&gb) << 8;
 240                     dst32[2] = bytestream2_get_be24u(&gb) << 8;
 241                     dst32[4] = bytestream2_get_be24u(&gb) << 8;
 242                     dst32[5] = bytestream2_get_be24u(&gb) << 8;
 243                     dst32[3] = bytestream2_get_be24u(&gb) << 8;
 244                     dst32 += 6;
 245                 } while (--samples);
 246             }
 247             break;
 248             /* remapping: L, R, C, LSide, LBack, RBack, RSide, <unused> */
 249         case AV_CH_LAYOUT_7POINT0:
 250             if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
 251                 do {
 252                     dst16[0] = bytestream2_get_be16u(&gb);
 253                     dst16[1] = bytestream2_get_be16u(&gb);
 254                     dst16[2] = bytestream2_get_be16u(&gb);
 255                     dst16[5] = bytestream2_get_be16u(&gb);
 256                     dst16[3] = bytestream2_get_be16u(&gb);
 257                     dst16[4] = bytestream2_get_be16u(&gb);
 258                     dst16[6] = bytestream2_get_be16u(&gb);
 259                     dst16 += 7;
 260                     bytestream2_skip(&gb, 2);
 261                 } while (--samples);
 262             } else {
 263                 do {
 264                     dst32[0] = bytestream2_get_be24u(&gb) << 8;
 265                     dst32[1] = bytestream2_get_be24u(&gb) << 8;
 266                     dst32[2] = bytestream2_get_be24u(&gb) << 8;
 267                     dst32[5] = bytestream2_get_be24u(&gb) << 8;
 268                     dst32[3] = bytestream2_get_be24u(&gb) << 8;
 269                     dst32[4] = bytestream2_get_be24u(&gb) << 8;
 270                     dst32[6] = bytestream2_get_be24u(&gb) << 8;
 271                     dst32 += 7;
 272                     bytestream2_skip(&gb, 3);
 273                 } while (--samples);
 274             }
 275             break;
 276             /* remapping: L, R, C, LSide, LBack, RBack, RSide, LF */
 277         case AV_CH_LAYOUT_7POINT1:
 278             if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) {
 279                 do {
 280                     dst16[0] = bytestream2_get_be16u(&gb);
 281                     dst16[1] = bytestream2_get_be16u(&gb);
 282                     dst16[2] = bytestream2_get_be16u(&gb);
 283                     dst16[6] = bytestream2_get_be16u(&gb);
 284                     dst16[4] = bytestream2_get_be16u(&gb);
 285                     dst16[5] = bytestream2_get_be16u(&gb);
 286                     dst16[7] = bytestream2_get_be16u(&gb);
 287                     dst16[3] = bytestream2_get_be16u(&gb);
 288                     dst16 += 8;
 289                 } while (--samples);
 290             } else {
 291                 do {
 292                     dst32[0] = bytestream2_get_be24u(&gb) << 8;
 293                     dst32[1] = bytestream2_get_be24u(&gb) << 8;
 294                     dst32[2] = bytestream2_get_be24u(&gb) << 8;
 295                     dst32[6] = bytestream2_get_be24u(&gb) << 8;
 296                     dst32[4] = bytestream2_get_be24u(&gb) << 8;
 297                     dst32[5] = bytestream2_get_be24u(&gb) << 8;
 298                     dst32[7] = bytestream2_get_be24u(&gb) << 8;
 299                     dst32[3] = bytestream2_get_be24u(&gb) << 8;
 300                     dst32 += 8;
 301                 } while (--samples);
 302             }
 303             break;
 304         }
 305     }
 306
 307     *got_frame_ptr   = 1;
 308     *(AVFrame *)data = s->frame;
 309
 310     retval = bytestream2_tell(&gb);
 311     if (avctx->debug & FF_DEBUG_BITSTREAM)
 312         av_dlog(avctx, "pcm_bluray_decode_frame: decoded %d -> %d bytes\n",
 313                 retval, buf_size);
 314     return retval + 4;
 315 }
 316
 317 AVCodec ff_pcm_bluray_decoder = {
 318     .name           = "pcm_bluray",
 319     .type           = AVMEDIA_TYPE_AUDIO,
 320     .id             = AV_CODEC_ID_PCM_BLURAY,
 321     .priv_data_size = sizeof(PCMBRDecode),
 322     .init           = pcm_bluray_decode_init,
 323     .decode         = pcm_bluray_decode_frame,
 324     .capabilities   = CODEC_CAP_DR1,
 325     .sample_fmts    = (const enum AVSampleFormat[]){
 326         AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_NONE
 327     },
 328     .long_name      = NULL_IF_CONFIG_SMALL("PCM signed 16|20|24-bit big-endian for Blu-ray media"),
 329 };