/* * LPCM codecs for PCM formats found in MPEG streams * Copyright (c) 2009 Christian Schmidt * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * PCM codecs for encodings found in MPEG streams (DVD/Blu-ray) */ #include "avcodec.h" #include "bytestream.h" /* * Channel Mapping according to * Blu-ray Disc Read-Only Format Version 1 * Part 3: Audio Visual Basic Specifications * mono M1 X * stereo L R * 3/0 L R C X * 2/1 L R S X * 3/1 L R C S * 2/2 L R LS RS * 3/2 L R C LS RS X * 3/2+lfe L R C LS RS lfe * 3/4 L R C LS Rls Rrs RS X * 3/4+lfe L R C LS Rls Rrs RS lfe */ /** * Parse the header of a LPCM frame read from a MPEG-TS stream * @param avctx the codec context * @param header pointer to the first four bytes of the data packet */ static int pcm_bluray_parse_header(AVCodecContext *avctx, const uint8_t *header) { static const uint8_t bits_per_samples[4] = { 0, 16, 20, 24 }; static const uint32_t channel_layouts[16] = { 0, CH_LAYOUT_MONO, 0, CH_LAYOUT_STEREO, CH_LAYOUT_SURROUND, CH_LAYOUT_2_1, CH_LAYOUT_4POINT0, CH_LAYOUT_2_2, CH_LAYOUT_5POINT0, CH_LAYOUT_5POINT1, CH_LAYOUT_7POINT0, CH_LAYOUT_7POINT1, 0, 0, 0, 0 }; static const uint8_t channels[16] = { 0, 1, 0, 2, 3, 3, 4, 4, 5, 6, 7, 8, 0, 0, 0, 0 }; uint8_t channel_layout = header[2] >> 4; if (avctx->debug & FF_DEBUG_PICT_INFO) dprintf(avctx, "pcm_bluray_parse_header: header = %02x%02x%02x%02x\n", header[0], header[1], header[2], header[3]); /* get the sample depth and derive the sample format from it */ avctx->bits_per_coded_sample = bits_per_samples[header[3] >> 6]; if (!avctx->bits_per_coded_sample) { av_log(avctx, AV_LOG_ERROR, "unsupported sample depth (0)\n"); return -1; } avctx->sample_fmt = avctx->bits_per_coded_sample == 16 ? SAMPLE_FMT_S16 : SAMPLE_FMT_S32; /* get the sample rate. Not all values are known or exist. */ switch (header[2] & 0x0f) { case 1: avctx->sample_rate = 48000; break; case 4: avctx->sample_rate = 96000; break; case 5: avctx->sample_rate = 192000; break; default: avctx->sample_rate = 0; av_log(avctx, AV_LOG_ERROR, "unsupported sample rate (%d)\n", header[2] & 0x0f); return -1; } /* * get the channel number (and mapping). Not all values are known or exist. * It must be noted that the number of channels in the MPEG stream can * differ from the actual meaningful number, e.g. mono audio still has two * channels, one being empty. */ avctx->channel_layout = channel_layouts[channel_layout]; avctx->channels = channels[channel_layout]; if (!avctx->channels) { av_log(avctx, AV_LOG_ERROR, "unsupported channel configuration (%d)\n", channel_layout); return -1; } avctx->bit_rate = avctx->channels * avctx->sample_rate * avctx->bits_per_coded_sample; if (avctx->debug & FF_DEBUG_PICT_INFO) dprintf(avctx, "pcm_bluray_parse_header: %d channels, %d bits per sample, %d kHz, %d kbit\n", avctx->channels, avctx->bits_per_coded_sample, avctx->sample_rate, avctx->bit_rate); return 0; } static int pcm_bluray_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt) { const uint8_t *src = avpkt->data; int buf_size = avpkt->size; int num_source_channels, channel, retval; int sample_size, samples, output_size; int16_t *dst16 = data; int32_t *dst32 = data; if (buf_size < 4) { av_log(avctx, AV_LOG_ERROR, "PCM packet too small\n"); return -1; } if (pcm_bluray_parse_header(avctx, src)) return -1; src += 4; buf_size -= 4; /* There's always an even number of channels in the source */ num_source_channels = FFALIGN(avctx->channels, 2); sample_size = (num_source_channels * avctx->bits_per_coded_sample) >> 3; samples = buf_size / sample_size; output_size = samples * avctx->channels * (avctx->sample_fmt == SAMPLE_FMT_S32 ? 4 : 2); if (output_size > *data_size) { av_log(avctx, AV_LOG_ERROR, "Insufficient output buffer space (%d bytes, needed %d bytes)\n", *data_size, output_size); return -1; } *data_size = output_size; if (samples) { switch (avctx->channel_layout) { /* cases with same number of source and coded channels */ case CH_LAYOUT_STEREO: case CH_LAYOUT_4POINT0: case CH_LAYOUT_2_2: samples *= num_source_channels; if (SAMPLE_FMT_S16 == avctx->sample_fmt) { #if HAVE_BIGENDIAN memcpy(dst16, src, output_size); #else do { *dst16++ = bytestream_get_be16(&src); } while (--samples); #endif } else { do { *dst32++ = bytestream_get_be24(&src) << 8; } while (--samples); } break; /* cases where number of source channels = coded channels + 1 */ case CH_LAYOUT_MONO: case CH_LAYOUT_SURROUND: case CH_LAYOUT_2_1: case CH_LAYOUT_5POINT0: if (SAMPLE_FMT_S16 == avctx->sample_fmt) { do { #if HAVE_BIGENDIAN memcpy(dst16, src, avctx->channels * 2); dst16 += avctx->channels; src += sample_size; #else channel = avctx->channels; do { *dst16++ = bytestream_get_be16(&src); } while (--channel); src += 2; #endif } while (--samples); } else { do { channel = avctx->channels; do { *dst32++ = bytestream_get_be24(&src) << 8; } while (--channel); src += 3; } while (--samples); } break; /* remapping: L, R, C, LBack, RBack, LF */ case CH_LAYOUT_5POINT1: if (SAMPLE_FMT_S16 == avctx->sample_fmt) { do { dst16[0] = bytestream_get_be16(&src); dst16[1] = bytestream_get_be16(&src); dst16[2] = bytestream_get_be16(&src); dst16[4] = bytestream_get_be16(&src); dst16[5] = bytestream_get_be16(&src); dst16[3] = bytestream_get_be16(&src); dst16 += 6; } while (--samples); } else { do { dst32[0] = bytestream_get_be24(&src) << 8; dst32[1] = bytestream_get_be24(&src) << 8; dst32[2] = bytestream_get_be24(&src) << 8; dst32[4] = bytestream_get_be24(&src) << 8; dst32[5] = bytestream_get_be24(&src) << 8; dst32[3] = bytestream_get_be24(&src) << 8; dst32 += 6; } while (--samples); } break; /* remapping: L, R, C, LSide, LBack, RBack, RSide, */ case CH_LAYOUT_7POINT0: if (SAMPLE_FMT_S16 == avctx->sample_fmt) { do { dst16[0] = bytestream_get_be16(&src); dst16[1] = bytestream_get_be16(&src); dst16[2] = bytestream_get_be16(&src); dst16[5] = bytestream_get_be16(&src); dst16[3] = bytestream_get_be16(&src); dst16[4] = bytestream_get_be16(&src); dst16[6] = bytestream_get_be16(&src); dst16 += 7; src += 2; } while (--samples); } else { do { dst32[0] = bytestream_get_be24(&src) << 8; dst32[1] = bytestream_get_be24(&src) << 8; dst32[2] = bytestream_get_be24(&src) << 8; dst32[5] = bytestream_get_be24(&src) << 8; dst32[3] = bytestream_get_be24(&src) << 8; dst32[4] = bytestream_get_be24(&src) << 8; dst32[6] = bytestream_get_be24(&src) << 8; dst32 += 7; src += 3; } while (--samples); } break; /* remapping: L, R, C, LSide, LBack, RBack, RSide, LF */ case CH_LAYOUT_7POINT1: if (SAMPLE_FMT_S16 == avctx->sample_fmt) { do { dst16[0] = bytestream_get_be16(&src); dst16[1] = bytestream_get_be16(&src); dst16[2] = bytestream_get_be16(&src); dst16[6] = bytestream_get_be16(&src); dst16[4] = bytestream_get_be16(&src); dst16[5] = bytestream_get_be16(&src); dst16[7] = bytestream_get_be16(&src); dst16[3] = bytestream_get_be16(&src); dst16 += 8; } while (--samples); } else { do { dst32[0] = bytestream_get_be24(&src) << 8; dst32[1] = bytestream_get_be24(&src) << 8; dst32[2] = bytestream_get_be24(&src) << 8; dst32[6] = bytestream_get_be24(&src) << 8; dst32[4] = bytestream_get_be24(&src) << 8; dst32[5] = bytestream_get_be24(&src) << 8; dst32[7] = bytestream_get_be24(&src) << 8; dst32[3] = bytestream_get_be24(&src) << 8; dst32 += 8; } while (--samples); } break; } } retval = src - avpkt->data; if (avctx->debug & FF_DEBUG_BITSTREAM) dprintf(avctx, "pcm_bluray_decode_frame: decoded %d -> %d bytes\n", retval, *data_size); return retval; } AVCodec pcm_bluray_decoder = { "pcm_bluray", AVMEDIA_TYPE_AUDIO, CODEC_ID_PCM_BLURAY, 0, NULL, NULL, NULL, pcm_bluray_decode_frame, .sample_fmts = (const enum SampleFormat[]){SAMPLE_FMT_S16, SAMPLE_FMT_S32, SAMPLE_FMT_NONE}, .long_name = NULL_IF_CONFIG_SMALL("PCM signed 16|20|24-bit big-endian for Blu-ray media"), };