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 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 libavcodec/pcm-mpeg.c
  24  * PCM codecs for encodings found in MPEG streams (DVD/Blu-ray)
  25  */
  26
  27 #include "avcodec.h"
  28 #include "bytestream.h"
  29
  30 /*
  31  * Channel Mapping according to
  32  * Blu-ray Disc Read-Only Format Version 1
  33  * Part 3: Audio Visual Basic Specifications
  34  * mono     M1    X
  35  * stereo   L     R
  36  * 3/0      L     R    C    X
  37  * 2/1      L     R    S    X
  38  * 3/1      L     R    C    S
  39  * 2/2      L     R    LS   RS
  40  * 3/2      L     R    C    LS    RS    X
  41  * 3/2+lfe  L     R    C    LS    RS    lfe
  42  * 3/4      L     R    C    LS    Rls   Rrs  RS   X
  43  * 3/4+lfe  L     R    C    LS    Rls   Rrs  RS   lfe
  44  */
  45
  46 /**
  47  * Parse the header of a LPCM frame read from a MPEG-TS stream
  48  * @param avctx the codec context
  49  * @param header pointer to the first four bytes of the data packet
  50  */
  51 static int pcm_bluray_parse_header(AVCodecContext *avctx,
  52                                    const uint8_t *header)
  53 {
  54     static const uint8_t bits_per_samples[4] = { 0, 16, 20, 24 };
  55     static const uint32_t channel_layouts[16] = {
  56         0, CH_LAYOUT_MONO, 0, CH_LAYOUT_STEREO, CH_LAYOUT_SURROUND,
  57         CH_LAYOUT_2_1, CH_LAYOUT_4POINT0, CH_LAYOUT_2_2, CH_LAYOUT_5POINT0,
  58         CH_LAYOUT_5POINT1, CH_LAYOUT_7POINT0, CH_LAYOUT_7POINT1, 0, 0, 0, 0
  59     };
  60     static const uint8_t channels[16] = {
  61         0, 1, 0, 2, 3, 3, 4, 4, 5, 6, 7, 8, 0, 0, 0, 0
  62     };
  63     uint8_t channel_layout = header[2] >> 4;
  64
  65     if (avctx->debug & FF_DEBUG_PICT_INFO)
  66         dprintf(avctx, "pcm_bluray_parse_header: header = %02x%02x%02x%02x\n",
  67                 header[0], header[1], header[2], header[3]);
  68
  69     /* get the sample depth and derive the sample format from it */
  70     avctx->bits_per_coded_sample = bits_per_samples[header[3] >> 6];
  71     if (!avctx->bits_per_coded_sample) {
  72         av_log(avctx, AV_LOG_ERROR, "unsupported sample depth (0)\n");
  73         return -1;
  74     }
  75     avctx->sample_fmt = avctx->bits_per_coded_sample == 16 ? SAMPLE_FMT_S16 :
  76                                                              SAMPLE_FMT_S32;
  77
  78     /* get the sample rate. Not all values are known or exist. */
  79     switch (header[2] & 0x0f) {
  80     case 1:
  81         avctx->sample_rate = 48000;
  82         break;
  83     case 4:
  84         avctx->sample_rate = 96000;
  85         break;
  86     case 5:
  87         avctx->sample_rate = 192000;
  88         break;
  89     default:
  90         avctx->sample_rate = 0;
  91         av_log(avctx, AV_LOG_ERROR, "unsupported sample rate (%d)\n",
  92                header[2] & 0x0f);
  93         return -1;
  94     }
  95
  96     /*
  97      * get the channel number (and mapping). Not all values are known or exist.
  98      * It must be noted that the number of channels in the MPEG stream can
  99      * differ from the actual meaningful number, e.g. mono audio still has two
 100      * channels, one being empty.
 101      */
 102     avctx->channel_layout  = channel_layouts[channel_layout];
 103     avctx->channels        =        channels[channel_layout];
 104     if (!avctx->channels) {
 105         av_log(avctx, AV_LOG_ERROR, "unsupported channel configuration (%d)\n",
 106                channel_layout);
 107         return -1;
 108     }
 109
 110     avctx->bit_rate = avctx->channels * avctx->sample_rate *
 111                       avctx->bits_per_coded_sample;
 112
 113     if (avctx->debug & FF_DEBUG_PICT_INFO)
 114         dprintf(avctx,
 115                 "pcm_bluray_parse_header: %d channels, %d bits per sample, %d kHz, %d kbit\n",
 116                 avctx->channels, avctx->bits_per_coded_sample,
 117                 avctx->sample_rate, avctx->bit_rate);
 118     return 0;
 119 }
 120
 121 static int pcm_bluray_decode_frame(AVCodecContext *avctx,
 122                                    void *data,
 123                                    int *data_size,
 124                                    AVPacket *avpkt)
 125 {
 126     const uint8_t *src = avpkt->data;
 127     int buf_size = avpkt->size;
 128     int num_source_channels, channel, retval;
 129     int sample_size, samples, output_size;
 130     int16_t *dst16 = data;
 131     int32_t *dst32 = data;
 132
 133     if (buf_size < 4) {
 134         av_log(avctx, AV_LOG_ERROR, "PCM packet too small\n");
 135         return -1;
 136     }
 137
 138     if (pcm_bluray_parse_header(avctx, src))
 139         return -1;
 140     src += 4;
 141     buf_size -= 4;
 142
 143     /* There's always an even number of channels in the source */
 144     num_source_channels = FFALIGN(avctx->channels, 2);
 145     sample_size = (num_source_channels * avctx->bits_per_coded_sample) >> 3;
 146     samples = buf_size / sample_size;
 147
 148     output_size = samples * avctx->channels *
 149                   (avctx->sample_fmt == SAMPLE_FMT_S32 ? 4 : 2);
 150     if (output_size > *data_size) {
 151         av_log(avctx, AV_LOG_ERROR,
 152                "Insufficient output buffer space (%d bytes, needed %d bytes)\n",
 153                *data_size, output_size);
 154         return -1;
 155     }
 156     *data_size = output_size;
 157
 158     if (samples) {
 159         switch (avctx->channel_layout) {
 160             /* cases with same number of source and coded channels */
 161         case CH_LAYOUT_STEREO:
 162         case CH_LAYOUT_4POINT0:
 163         case CH_LAYOUT_2_2:
 164             samples *= num_source_channels;
 165             if (SAMPLE_FMT_S16 == avctx->sample_fmt) {
 166 #if HAVE_BIGENDIAN
 167                 memcpy(dst16, src, output_size);
 168 #else
 169                 do {
 170                     *dst16++ = bytestream_get_be16(&src);
 171                 } while (--samples);
 172 #endif
 173             } else {
 174                 do {
 175                     *dst32++ = bytestream_get_be24(&src) << 8;
 176                 } while (--samples);
 177             }
 178             break;
 179         /* cases where number of source channels = coded channels + 1 */
 180         case CH_LAYOUT_MONO:
 181         case CH_LAYOUT_SURROUND:
 182         case CH_LAYOUT_2_1:
 183         case CH_LAYOUT_5POINT0:
 184             if (SAMPLE_FMT_S16 == avctx->sample_fmt) {
 185                 do {
 186 #if HAVE_BIGENDIAN
 187                     memcpy(dst16, src, avctx->channels * 2);
 188                     dst16 += avctx->channels;
 189                     src += sample_size;
 190 #else
 191                     channel = avctx->channels;
 192                     do {
 193                         *dst16++ = bytestream_get_be16(&src);
 194                     } while (--channel);
 195                     src += 2;
 196 #endif
 197                 } while (--samples);
 198             } else {
 199                 do {
 200                     channel = avctx->channels;
 201                     do {
 202                         *dst32++ = bytestream_get_be24(&src) << 8;
 203                     } while (--channel);
 204                     src += 3;
 205                 } while (--samples);
 206             }
 207             break;
 208             /* remapping: L, R, C, LBack, RBack, LF */
 209         case CH_LAYOUT_5POINT1:
 210             if (SAMPLE_FMT_S16 == avctx->sample_fmt) {
 211                 do {
 212                     dst16[0] = bytestream_get_be16(&src);
 213                     dst16[1] = bytestream_get_be16(&src);
 214                     dst16[2] = bytestream_get_be16(&src);
 215                     dst16[4] = bytestream_get_be16(&src);
 216                     dst16[5] = bytestream_get_be16(&src);
 217                     dst16[3] = bytestream_get_be16(&src);
 218                     dst16 += 6;
 219                 } while (--samples);
 220             } else {
 221                 do {
 222                     dst32[0] = bytestream_get_be24(&src) << 8;
 223                     dst32[1] = bytestream_get_be24(&src) << 8;
 224                     dst32[2] = bytestream_get_be24(&src) << 8;
 225                     dst32[4] = bytestream_get_be24(&src) << 8;
 226                     dst32[5] = bytestream_get_be24(&src) << 8;
 227                     dst32[3] = bytestream_get_be24(&src) << 8;
 228                     dst32 += 6;
 229                 } while (--samples);
 230             }
 231             break;
 232             /* remapping: L, R, C, LSide, LBack, RBack, RSide, <unused> */
 233         case CH_LAYOUT_7POINT0:
 234             if (SAMPLE_FMT_S16 == avctx->sample_fmt) {
 235                 do {
 236                     dst16[0] = bytestream_get_be16(&src);
 237                     dst16[1] = bytestream_get_be16(&src);
 238                     dst16[2] = bytestream_get_be16(&src);
 239                     dst16[5] = bytestream_get_be16(&src);
 240                     dst16[3] = bytestream_get_be16(&src);
 241                     dst16[4] = bytestream_get_be16(&src);
 242                     dst16[6] = bytestream_get_be16(&src);
 243                     dst16 += 7;
 244                     src += 2;
 245                 } while (--samples);
 246             } else {
 247                 do {
 248                     dst32[0] = bytestream_get_be24(&src) << 8;
 249                     dst32[1] = bytestream_get_be24(&src) << 8;
 250                     dst32[2] = bytestream_get_be24(&src) << 8;
 251                     dst32[5] = bytestream_get_be24(&src) << 8;
 252                     dst32[3] = bytestream_get_be24(&src) << 8;
 253                     dst32[4] = bytestream_get_be24(&src) << 8;
 254                     dst32[6] = bytestream_get_be24(&src) << 8;
 255                     dst32 += 7;
 256                     src += 3;
 257                 } while (--samples);
 258             }
 259             break;
 260             /* remapping: L, R, C, LSide, LBack, RBack, RSide, LF */
 261         case CH_LAYOUT_7POINT1:
 262             if (SAMPLE_FMT_S16 == avctx->sample_fmt) {
 263                 do {
 264                     dst16[0] = bytestream_get_be16(&src);
 265                     dst16[1] = bytestream_get_be16(&src);
 266                     dst16[2] = bytestream_get_be16(&src);
 267                     dst16[6] = bytestream_get_be16(&src);
 268                     dst16[4] = bytestream_get_be16(&src);
 269                     dst16[5] = bytestream_get_be16(&src);
 270                     dst16[7] = bytestream_get_be16(&src);
 271                     dst16[3] = bytestream_get_be16(&src);
 272                     dst16 += 8;
 273                 } while (--samples);
 274             } else {
 275                 do {
 276                     dst32[0] = bytestream_get_be24(&src) << 8;
 277                     dst32[1] = bytestream_get_be24(&src) << 8;
 278                     dst32[2] = bytestream_get_be24(&src) << 8;
 279                     dst32[6] = bytestream_get_be24(&src) << 8;
 280                     dst32[4] = bytestream_get_be24(&src) << 8;
 281                     dst32[5] = bytestream_get_be24(&src) << 8;
 282                     dst32[7] = bytestream_get_be24(&src) << 8;
 283                     dst32[3] = bytestream_get_be24(&src) << 8;
 284                     dst32 += 8;
 285                 } while (--samples);
 286             }
 287             break;
 288         }
 289     }
 290
 291     retval = src - avpkt->data;
 292     if (avctx->debug & FF_DEBUG_BITSTREAM)
 293         dprintf(avctx, "pcm_bluray_decode_frame: decoded %d -> %d bytes\n",
 294                 retval, *data_size);
 295     return retval;
 296 }
 297
 298 AVCodec pcm_bluray_decoder = {
 299     "pcm_bluray",
 300     CODEC_TYPE_AUDIO,
 301     CODEC_ID_PCM_BLURAY,
 302     0,
 303     NULL,
 304     NULL,
 305     NULL,
 306     pcm_bluray_decode_frame,
 307     .sample_fmts = (const enum SampleFormat[]){SAMPLE_FMT_S16, SAMPLE_FMT_S32,
 308                                          SAMPLE_FMT_NONE},
 309     .long_name = NULL_IF_CONFIG_SMALL("PCM signed 16|20|24-bit big-endian for Blu-ray media"),
 310 };