/* * LPCM codecs for PCM formats found in MPEG streams * Copyright (c) 2009 Christian Schmidt * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; 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 "libavutil/channel_layout.h" #include "avcodec.h" #include "bytestream.h" #include "internal.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, AV_CH_LAYOUT_MONO, 0, AV_CH_LAYOUT_STEREO, AV_CH_LAYOUT_SURROUND, AV_CH_LAYOUT_2_1, AV_CH_LAYOUT_4POINT0, AV_CH_LAYOUT_2_2, AV_CH_LAYOUT_5POINT0, AV_CH_LAYOUT_5POINT1, AV_CH_LAYOUT_7POINT0, AV_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) av_dlog(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, "reserved sample depth (0)\n"); return -1; } avctx->sample_fmt = avctx->bits_per_coded_sample == 16 ? AV_SAMPLE_FMT_S16 : AV_SAMPLE_FMT_S32; avctx->bits_per_raw_sample = avctx->bits_per_coded_sample; /* get the sample rate. Not all values are used. */ 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, "reserved sample rate (%d)\n", header[2] & 0x0f); return -1; } /* * get the channel number (and mapping). Not all values are used. * 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, "reserved channel configuration (%d)\n", channel_layout); return -1; } avctx->bit_rate = FFALIGN(avctx->channels, 2) * avctx->sample_rate * avctx->bits_per_coded_sample; if (avctx->debug & FF_DEBUG_PICT_INFO) av_dlog(avctx, "pcm_bluray_parse_header: %d channels, %d bits per sample, %d Hz, %d bit/s\n", avctx->channels, avctx->bits_per_coded_sample, avctx->sample_rate, avctx->bit_rate); return 0; } typedef struct PCMBRDecode { AVFrame frame; } PCMBRDecode; static av_cold int pcm_bluray_decode_init(AVCodecContext * avctx) { PCMBRDecode *s = avctx->priv_data; avcodec_get_frame_defaults(&s->frame); avctx->coded_frame = &s->frame; return 0; } static int pcm_bluray_decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt) { const uint8_t *src = avpkt->data; int buf_size = avpkt->size; PCMBRDecode *s = avctx->priv_data; GetByteContext gb; int num_source_channels, channel, retval; int sample_size, samples; int16_t *dst16; int32_t *dst32; 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; bytestream2_init(&gb, src, buf_size); /* There's always an even number of channels in the source */ num_source_channels = FFALIGN(avctx->channels, 2); sample_size = (num_source_channels * (avctx->sample_fmt == AV_SAMPLE_FMT_S16 ? 16 : 24)) >> 3; samples = buf_size / sample_size; /* get output buffer */ s->frame.nb_samples = samples; if ((retval = ff_get_buffer(avctx, &s->frame)) < 0) { av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return retval; } dst16 = (int16_t *)s->frame.data[0]; dst32 = (int32_t *)s->frame.data[0]; if (samples) { switch (avctx->channel_layout) { /* cases with same number of source and coded channels */ case AV_CH_LAYOUT_STEREO: case AV_CH_LAYOUT_4POINT0: case AV_CH_LAYOUT_2_2: samples *= num_source_channels; if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) { #if HAVE_BIGENDIAN bytestream2_get_buffer(&gb, dst16, buf_size); #else do { *dst16++ = bytestream2_get_be16u(&gb); } while (--samples); #endif } else { do { *dst32++ = bytestream2_get_be24u(&gb) << 8; } while (--samples); } break; /* cases where number of source channels = coded channels + 1 */ case AV_CH_LAYOUT_MONO: case AV_CH_LAYOUT_SURROUND: case AV_CH_LAYOUT_2_1: case AV_CH_LAYOUT_5POINT0: if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) { do { #if HAVE_BIGENDIAN bytestream2_get_buffer(&gb, dst16, avctx->channels * 2); dst16 += avctx->channels; #else channel = avctx->channels; do { *dst16++ = bytestream2_get_be16u(&gb); } while (--channel); #endif bytestream2_skip(&gb, 2); } while (--samples); } else { do { channel = avctx->channels; do { *dst32++ = bytestream2_get_be24u(&gb) << 8; } while (--channel); bytestream2_skip(&gb, 3); } while (--samples); } break; /* remapping: L, R, C, LBack, RBack, LF */ case AV_CH_LAYOUT_5POINT1: if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) { do { dst16[0] = bytestream2_get_be16u(&gb); dst16[1] = bytestream2_get_be16u(&gb); dst16[2] = bytestream2_get_be16u(&gb); dst16[4] = bytestream2_get_be16u(&gb); dst16[5] = bytestream2_get_be16u(&gb); dst16[3] = bytestream2_get_be16u(&gb); dst16 += 6; } while (--samples); } else { do { dst32[0] = bytestream2_get_be24u(&gb) << 8; dst32[1] = bytestream2_get_be24u(&gb) << 8; dst32[2] = bytestream2_get_be24u(&gb) << 8; dst32[4] = bytestream2_get_be24u(&gb) << 8; dst32[5] = bytestream2_get_be24u(&gb) << 8; dst32[3] = bytestream2_get_be24u(&gb) << 8; dst32 += 6; } while (--samples); } break; /* remapping: L, R, C, LSide, LBack, RBack, RSide, <unused> */ case AV_CH_LAYOUT_7POINT0: if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) { do { dst16[0] = bytestream2_get_be16u(&gb); dst16[1] = bytestream2_get_be16u(&gb); dst16[2] = bytestream2_get_be16u(&gb); dst16[5] = bytestream2_get_be16u(&gb); dst16[3] = bytestream2_get_be16u(&gb); dst16[4] = bytestream2_get_be16u(&gb); dst16[6] = bytestream2_get_be16u(&gb); dst16 += 7; bytestream2_skip(&gb, 2); } while (--samples); } else { do { dst32[0] = bytestream2_get_be24u(&gb) << 8; dst32[1] = bytestream2_get_be24u(&gb) << 8; dst32[2] = bytestream2_get_be24u(&gb) << 8; dst32[5] = bytestream2_get_be24u(&gb) << 8; dst32[3] = bytestream2_get_be24u(&gb) << 8; dst32[4] = bytestream2_get_be24u(&gb) << 8; dst32[6] = bytestream2_get_be24u(&gb) << 8; dst32 += 7; bytestream2_skip(&gb, 3); } while (--samples); } break; /* remapping: L, R, C, LSide, LBack, RBack, RSide, LF */ case AV_CH_LAYOUT_7POINT1: if (AV_SAMPLE_FMT_S16 == avctx->sample_fmt) { do { dst16[0] = bytestream2_get_be16u(&gb); dst16[1] = bytestream2_get_be16u(&gb); dst16[2] = bytestream2_get_be16u(&gb); dst16[6] = bytestream2_get_be16u(&gb); dst16[4] = bytestream2_get_be16u(&gb); dst16[5] = bytestream2_get_be16u(&gb); dst16[7] = bytestream2_get_be16u(&gb); dst16[3] = bytestream2_get_be16u(&gb); dst16 += 8; } while (--samples); } else { do { dst32[0] = bytestream2_get_be24u(&gb) << 8; dst32[1] = bytestream2_get_be24u(&gb) << 8; dst32[2] = bytestream2_get_be24u(&gb) << 8; dst32[6] = bytestream2_get_be24u(&gb) << 8; dst32[4] = bytestream2_get_be24u(&gb) << 8; dst32[5] = bytestream2_get_be24u(&gb) << 8; dst32[7] = bytestream2_get_be24u(&gb) << 8; dst32[3] = bytestream2_get_be24u(&gb) << 8; dst32 += 8; } while (--samples); } break; } } *got_frame_ptr = 1; *(AVFrame *)data = s->frame; retval = bytestream2_tell(&gb); if (avctx->debug & FF_DEBUG_BITSTREAM) av_dlog(avctx, "pcm_bluray_decode_frame: decoded %d -> %d bytes\n", retval, buf_size); return retval + 4; } AVCodec ff_pcm_bluray_decoder = { .name = "pcm_bluray", .type = AVMEDIA_TYPE_AUDIO, .id = AV_CODEC_ID_PCM_BLURAY, .priv_data_size = sizeof(PCMBRDecode), .init = pcm_bluray_decode_init, .decode = pcm_bluray_decode_frame, .capabilities = CODEC_CAP_DR1, .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_NONE }, .long_name = NULL_IF_CONFIG_SMALL("PCM signed 16|20|24-bit big-endian for Blu-ray media"), };