From 6b493b2f2fd241f6b893f6aa549f10aee1b9ad0c Mon Sep 17 00:00:00 2001 From: Ian Caulfield Date: Wed, 28 Nov 2007 14:27:53 +0000 Subject: [PATCH] MLP/TrueHD parser Patch by Ian Caulfield, ian D caulfield gmail D com Thread: [PATCH] MLP/TrueHD decoder, 12 Oct 14:26 Originally committed as revision 11109 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/Makefile | 1 + libavcodec/allcodecs.c | 1 + libavcodec/mlp_parser.c | 307 ++++++++++++++++++++++++++++++++++++++++++++++++ libavcodec/mlp_parser.h | 58 +++++++++ 4 files changed, 367 insertions(+) create mode 100644 libavcodec/mlp_parser.c create mode 100644 libavcodec/mlp_parser.h diff --git a/libavcodec/Makefile b/libavcodec/Makefile index 7bc987c..de9f193 100644 --- a/libavcodec/Makefile +++ b/libavcodec/Makefile @@ -320,6 +320,7 @@ OBJS-$(CONFIG_H261_PARSER) += h261_parser.o OBJS-$(CONFIG_H263_PARSER) += h263_parser.o OBJS-$(CONFIG_H264_PARSER) += h264_parser.o OBJS-$(CONFIG_MJPEG_PARSER) += mjpeg_parser.o +OBJS-$(CONFIG_MLP_PARSER) += mlp_parser.o OBJS-$(CONFIG_MPEG4VIDEO_PARSER) += mpeg4video_parser.o h263.o OBJS-$(CONFIG_MPEGAUDIO_PARSER) += mpegaudio_parser.o mpegaudiodecheader.o mpegaudiodata.o OBJS-$(CONFIG_MPEGVIDEO_PARSER) += mpegvideo_parser.o diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c index 6984e52..d9c44d4 100644 --- a/libavcodec/allcodecs.c +++ b/libavcodec/allcodecs.c @@ -289,6 +289,7 @@ void avcodec_register_all(void) REGISTER_PARSER (H263, h263); REGISTER_PARSER (H264, h264); REGISTER_PARSER (MJPEG, mjpeg); + REGISTER_PARSER (MLP, mlp); REGISTER_PARSER (MPEG4VIDEO, mpeg4video); REGISTER_PARSER (MPEGAUDIO, mpegaudio); REGISTER_PARSER (MPEGVIDEO, mpegvideo); diff --git a/libavcodec/mlp_parser.c b/libavcodec/mlp_parser.c new file mode 100644 index 0000000..c946fcf --- /dev/null +++ b/libavcodec/mlp_parser.c @@ -0,0 +1,307 @@ +/* + * MLP parser + * Copyright (c) 2007 Ian Caulfield + * + * 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 mlp_parser.c + * MLP parser + */ + +#include "bitstream.h" +#include "parser.h" +#include "crc.h" +#include "mlp_parser.h" + +static const uint8_t mlp_quants[16] = { + 16, 20, 24, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, +}; + +static const uint8_t mlp_channels[32] = { + 1, 2, 3, 4, 3, 4, 5, 3, 4, 5, 4, 5, 6, 4, 5, 4, + 5, 6, 5, 5, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, +}; + +static const uint8_t thd_chancount[13] = { +// LR C LFE LRs LRvh LRc LRrs Cs Ts LRsd LRw Cvh LFE2 + 2, 1, 1, 2, 2, 2, 2, 1, 1, 2, 2, 1, 1 +}; + +static int mlp_samplerate(int in) +{ + if (in == 0xF) + return 0; + + return (in & 8 ? 44100 : 48000) << (in & 7) ; +} + +static int truehd_channels(int chanmap) +{ + int channels = 0, i; + + for (i = 0; i < 13; i++) + channels += thd_chancount[i] * ((chanmap >> i) & 1); + + return channels; +} + +static int crc_init = 0; +static AVCRC crc_2D[1024]; + +/** MLP uses checksums that seem to be based on the standard CRC algorithm, + * but not (in implementation terms, the table lookup and XOR are reversedi). + * We can implement this behaviour using a standard av_crc on all but the + * last element, then XOR that with the last element. + */ + +static uint16_t mlp_checksum16(const uint8_t *buf, unsigned int buf_size) +{ + uint16_t crc; + + if (!crc_init) { + av_crc_init(crc_2D, 0, 16, 0x002D, sizeof(crc_2D)); + crc_init = 1; + } + + crc = av_crc(crc_2D, 0, buf, buf_size - 2); + crc ^= AV_RL16(buf + buf_size - 2); + return crc; +} + +/** Read a major sync info header - contains high level information about + * the stream - sample rate, channel arrangement etc. Most of this + * information is not actually necessary for decoding, only for playback. + */ + +int ff_mlp_read_major_sync(void *log, MLPHeaderInfo *mh, const uint8_t *buf, + unsigned int buf_size) +{ + GetBitContext gb; + int ratebits; + uint16_t checksum; + + if (buf_size < 28) { + av_log(log, AV_LOG_ERROR, "Packet too short, unable to read major sync\n"); + return -1; + } + + checksum = mlp_checksum16(buf, 26); + if (checksum != AV_RL16(buf+26)) { + av_log(log, AV_LOG_ERROR, "Major sync info header checksum error\n"); + return -1; + } + + init_get_bits(&gb, buf, buf_size * 8); + + if (get_bits_long(&gb, 24) != 0xf8726f) /* Sync words */ + return -1; + + mh->stream_type = get_bits(&gb, 8); + + if (mh->stream_type == 0xbb) { + mh->group1_bits = mlp_quants[get_bits(&gb, 4)]; + mh->group2_bits = mlp_quants[get_bits(&gb, 4)]; + + ratebits = get_bits(&gb, 4); + mh->group1_samplerate = mlp_samplerate(ratebits); + mh->group2_samplerate = mlp_samplerate(get_bits(&gb, 4)); + + skip_bits(&gb, 11); + + mh->channels_mlp = get_bits(&gb, 5); + } else if (mh->stream_type == 0xba) { + mh->group1_bits = 24; // TODO: Is this information actually conveyed anywhere? + mh->group2_bits = 0; + + ratebits = get_bits(&gb, 4); + mh->group1_samplerate = mlp_samplerate(ratebits); + mh->group2_samplerate = 0; + + skip_bits(&gb, 8); + + mh->channels_thd_stream1 = get_bits(&gb, 5); + + skip_bits(&gb, 2); + + mh->channels_thd_stream2 = get_bits(&gb, 13); + } else + return -1; + + mh->access_unit_size = 40 << (ratebits & 7); + mh->access_unit_size_pow2 = 64 << (ratebits & 7); + + skip_bits_long(&gb, 48); + + mh->is_vbr = get_bits1(&gb); + + mh->peak_bitrate = (get_bits(&gb, 15) * mh->group1_samplerate + 8) >> 4; + + mh->num_substreams = get_bits(&gb, 4); + + skip_bits_long(&gb, 4 + 11 * 8); + + return 0; +} + +typedef struct MLPParseContext +{ + ParseContext pc; + + int bytes_left; + + int in_sync; + + int num_substreams; +} MLPParseContext; + +static int mlp_parse(AVCodecParserContext *s, + AVCodecContext *avctx, + const uint8_t **poutbuf, int *poutbuf_size, + const uint8_t *buf, int buf_size) +{ + MLPParseContext *mp = s->priv_data; + int sync_present; + uint8_t parity_bits; + int next; + int i, p = 0; + + *poutbuf_size = 0; + if (buf_size == 0) + return 0; + + if (!mp->in_sync) { + // Not in sync - find a major sync header + + for (i = 0; i < buf_size; i++) { + mp->pc.state = (mp->pc.state << 8) | buf[i]; + if ((mp->pc.state & 0xfffffffe) == 0xf8726fba) { + mp->in_sync = 1; + mp->bytes_left = 0; + break; + } + } + + if (!mp->in_sync) { + ff_combine_frame(&mp->pc, END_NOT_FOUND, &buf, &buf_size); + return buf_size; + } + + ff_combine_frame(&mp->pc, i - 7, &buf, &buf_size); + + return i - 7; + } + + if (mp->bytes_left == 0) { + // Find length of this packet + + /* Copy overread bytes from last frame into buffer. */ + for(; mp->pc.overread>0; mp->pc.overread--) { + mp->pc.buffer[mp->pc.index++]= mp->pc.buffer[mp->pc.overread_index++]; + } + + if (mp->pc.index + buf_size < 2) { + ff_combine_frame(&mp->pc, END_NOT_FOUND, &buf, &buf_size); + return buf_size; + } + + mp->bytes_left = ((mp->pc.index > 0 ? mp->pc.buffer[0] : buf[0]) << 8) + | (mp->pc.index > 1 ? mp->pc.buffer[1] : buf[1-mp->pc.index]); + mp->bytes_left = (mp->bytes_left & 0xfff) * 2; + mp->bytes_left -= mp->pc.index; + } + + next = (mp->bytes_left > buf_size) ? END_NOT_FOUND : mp->bytes_left; + + if (ff_combine_frame(&mp->pc, next, &buf, &buf_size) < 0) { + mp->bytes_left -= buf_size; + return buf_size; + } + + mp->bytes_left = 0; + + sync_present = (AV_RB32(buf + 4) & 0xfffffffe) == 0xf8726fba; + + if (!sync_present) { + // First nibble of a frame is a parity check of the first few nibbles + // Only check when this isn't a sync frame - syncs have a checksum + + parity_bits = 0; + for (i = 0; i <= mp->num_substreams; i++) { + parity_bits ^= buf[p++]; + parity_bits ^= buf[p++]; + + if (i == 0 || buf[p-2] & 0x80) { + parity_bits ^= buf[p++]; + parity_bits ^= buf[p++]; + } + } + + if ((((parity_bits >> 4) ^ parity_bits) & 0xF) != 0xF) { + av_log(avctx, AV_LOG_INFO, "mlpparse: parity check failed\n"); + goto lost_sync; + } + } else { + MLPHeaderInfo mh; + + if (ff_mlp_read_major_sync(avctx, &mh, buf + 4, buf_size - 4) < 0) + goto lost_sync; + +#ifdef CONFIG_AUDIO_NONSHORT + avctx->bits_per_sample = mh.group1_bits; + if (avctx->bits_per_sample > 16) + avctx->sample_fmt = SAMPLE_FMT_S32; +#endif + avctx->sample_rate = mh.group1_samplerate; + avctx->frame_size = mh.access_unit_size; + + if (mh.stream_type == 0xbb) { + /* MLP stream */ + avctx->channels = mlp_channels[mh.channels_mlp]; + } else { /* mh.stream_type == 0xba */ + /* TrueHD stream */ + if (mh.channels_thd_stream2) + avctx->channels = truehd_channels(mh.channels_thd_stream2); + else + avctx->channels = truehd_channels(mh.channels_thd_stream1); + } + + if (!mh.is_vbr) /* Stream is CBR */ + avctx->bit_rate = mh.peak_bitrate; + + mp->num_substreams = mh.num_substreams; + } + + *poutbuf = buf; + *poutbuf_size = buf_size; + + return next; + +lost_sync: + mp->in_sync = 0; + return -1; +} + +AVCodecParser mlp_parser = { + { CODEC_ID_MLP }, + sizeof(MLPParseContext), + NULL, + mlp_parse, + NULL, +}; diff --git a/libavcodec/mlp_parser.h b/libavcodec/mlp_parser.h new file mode 100644 index 0000000..3b7f43f --- /dev/null +++ b/libavcodec/mlp_parser.h @@ -0,0 +1,58 @@ +/* + * MLP parser prototypes + * Copyright (c) 2007 Ian Caulfield + * + * 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 mlp_parser.h + * MLP parser prototypes + */ + +#ifndef FFMPEG_MLP_PARSER_H +#define FFMPEG_MLP_PARSER_H + +typedef struct MLPHeaderInfo +{ + int stream_type; ///< 0xBB for MLP, 0xBA for TrueHD + + int group1_bits; ///< The bit depth of the first substream + int group2_bits; ///< Bit depth of the second substream (MLP only) + + int group1_samplerate; ///< Sample rate of first substream + int group2_samplerate; ///< Sample rate of second substream (MLP only) + + int channels_mlp; ///< Channel arrangement for MLP streams + int channels_thd_stream1; ///< Channel arrangement for substream 1 of TrueHD streams (5.1) + int channels_thd_stream2; ///< Channel arrangement for substream 2 of TrueHD streams (7.1) + + int access_unit_size; ///< Number of samples per coded frame + int access_unit_size_pow2; ///< Next power of two above number of samples per frame + + int is_vbr; ///< Stream is VBR instead of CBR + int peak_bitrate; ///< Peak bitrate for VBR, actual bitrate (==peak) for CBR + + int num_substreams; ///< Number of substreams within stream +} MLPHeaderInfo; + + +int ff_mlp_read_major_sync(void *log, MLPHeaderInfo *mh, const uint8_t *buf, + unsigned int buf_size); + +#endif /* FFMPEG_MLP_PARSER_H */ + -- 2.7.4