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 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 */ 51static 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 121static 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 298AVCodec pcm_bluray_decoder = { 299 "pcm_bluray", 300 AVMEDIA_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}; 311