| /* |
| * 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 |
| */ |
| |
| #include <stdint.h> |
| |
| #include "libavutil/channel_layout.h" |
| #include "libavutil/crc.h" |
| #include "libavutil/internal.h" |
| #include "get_bits.h" |
| #include "parser.h" |
| #include "mlp_parser.h" |
| #include "mlp.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, |
| }; |
| |
| const uint64_t ff_mlp_layout[32] = { |
| AV_CH_LAYOUT_MONO, |
| AV_CH_LAYOUT_STEREO, |
| AV_CH_LAYOUT_2_1, |
| AV_CH_LAYOUT_QUAD, |
| AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY, |
| AV_CH_LAYOUT_2_1|AV_CH_LOW_FREQUENCY, |
| AV_CH_LAYOUT_QUAD|AV_CH_LOW_FREQUENCY, |
| AV_CH_LAYOUT_SURROUND, |
| AV_CH_LAYOUT_4POINT0, |
| AV_CH_LAYOUT_5POINT0_BACK, |
| AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY, |
| AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY, |
| AV_CH_LAYOUT_5POINT1_BACK, |
| AV_CH_LAYOUT_4POINT0, |
| AV_CH_LAYOUT_5POINT0_BACK, |
| AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY, |
| AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY, |
| AV_CH_LAYOUT_5POINT1_BACK, |
| AV_CH_LAYOUT_QUAD|AV_CH_LOW_FREQUENCY, |
| AV_CH_LAYOUT_5POINT0_BACK, |
| AV_CH_LAYOUT_5POINT1_BACK, |
| 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 const uint64_t thd_layout[13] = { |
| AV_CH_FRONT_LEFT|AV_CH_FRONT_RIGHT, // LR |
| AV_CH_FRONT_CENTER, // C |
| AV_CH_LOW_FREQUENCY, // LFE |
| AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT, // LRs |
| AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT, // LRvh |
| AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER, // LRc |
| AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT, // LRrs |
| AV_CH_BACK_CENTER, // Cs |
| AV_CH_TOP_CENTER, // Ts |
| AV_CH_SURROUND_DIRECT_LEFT|AV_CH_SURROUND_DIRECT_RIGHT, // LRsd |
| AV_CH_WIDE_LEFT|AV_CH_WIDE_RIGHT, // LRw |
| AV_CH_TOP_FRONT_CENTER, // Cvh |
| AV_CH_LOW_FREQUENCY_2, // LFE2 |
| }; |
| |
| 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; |
| } |
| |
| uint64_t ff_truehd_layout(int chanmap) |
| { |
| int i; |
| uint64_t layout = 0; |
| |
| for (i = 0; i < 13; i++) |
| layout |= thd_layout[i] * ((chanmap >> i) & 1); |
| |
| return layout; |
| } |
| |
| static int ff_mlp_get_major_sync_size(const uint8_t * buf, int bufsize) |
| { |
| int has_extension, extensions = 0; |
| int size = 28; |
| if (bufsize < 28) |
| return -1; |
| |
| if (AV_RB32(buf) == 0xf8726fba) { |
| has_extension = buf[25] & 1; |
| if (has_extension) { |
| extensions = buf[26] >> 4; |
| size += 2 + extensions * 2; |
| } |
| } |
| return size; |
| } |
| |
| /** 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. |
| * gb must be a freshly initialized GetBitContext with no bits read. |
| */ |
| |
| int ff_mlp_read_major_sync(void *log, MLPHeaderInfo *mh, GetBitContext *gb) |
| { |
| int ratebits, channel_arrangement, header_size; |
| uint16_t checksum; |
| |
| av_assert1(get_bits_count(gb) == 0); |
| |
| header_size = ff_mlp_get_major_sync_size(gb->buffer, gb->size_in_bits >> 3); |
| if (header_size < 0 || gb->size_in_bits < header_size << 3) { |
| av_log(log, AV_LOG_ERROR, "packet too short, unable to read major sync\n"); |
| return -1; |
| } |
| |
| checksum = ff_mlp_checksum16(gb->buffer, header_size - 2); |
| if (checksum != AV_RL16(gb->buffer+header_size-2)) { |
| av_log(log, AV_LOG_ERROR, "major sync info header checksum error\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| if (get_bits_long(gb, 24) != 0xf8726f) /* Sync words */ |
| return AVERROR_INVALIDDATA; |
| |
| mh->stream_type = get_bits(gb, 8); |
| mh->header_size = header_size; |
| |
| 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->channel_arrangement= |
| channel_arrangement = get_bits(gb, 5); |
| mh->channels_mlp = mlp_channels[channel_arrangement]; |
| mh->channel_layout_mlp = ff_mlp_layout[channel_arrangement]; |
| } 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, 4); |
| |
| mh->channel_modifier_thd_stream0 = get_bits(gb, 2); |
| mh->channel_modifier_thd_stream1 = get_bits(gb, 2); |
| |
| mh->channel_arrangement= |
| channel_arrangement = get_bits(gb, 5); |
| mh->channels_thd_stream1 = truehd_channels(channel_arrangement); |
| mh->channel_layout_thd_stream1 = ff_truehd_layout(channel_arrangement); |
| |
| mh->channel_modifier_thd_stream2 = get_bits(gb, 2); |
| |
| channel_arrangement = get_bits(gb, 13); |
| mh->channels_thd_stream2 = truehd_channels(channel_arrangement); |
| mh->channel_layout_thd_stream2 = ff_truehd_layout(channel_arrangement); |
| } else |
| return AVERROR_INVALIDDATA; |
| |
| 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 + (header_size - 17) * 8); |
| |
| return 0; |
| } |
| |
| typedef struct MLPParseContext |
| { |
| ParseContext pc; |
| |
| int bytes_left; |
| |
| int in_sync; |
| |
| int num_substreams; |
| } MLPParseContext; |
| |
| static av_cold int mlp_init(AVCodecParserContext *s) |
| { |
| ff_mlp_init_crc(); |
| return 0; |
| } |
| |
| 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 ret; |
| 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 && |
| // ignore if we do not have the data for the start of header |
| mp->pc.index + i >= 7) { |
| mp->in_sync = 1; |
| mp->bytes_left = 0; |
| break; |
| } |
| } |
| |
| if (!mp->in_sync) { |
| if (ff_combine_frame(&mp->pc, END_NOT_FOUND, &buf, &buf_size) != -1) |
| av_log(avctx, AV_LOG_WARNING, "ff_combine_frame failed\n"); |
| return buf_size; |
| } |
| |
| if ((ret = ff_combine_frame(&mp->pc, i - 7, &buf, &buf_size)) < 0) { |
| av_log(avctx, AV_LOG_WARNING, "ff_combine_frame failed\n"); |
| return ret; |
| } |
| |
| 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) { |
| if (ff_combine_frame(&mp->pc, END_NOT_FOUND, &buf, &buf_size) != -1) |
| av_log(avctx, AV_LOG_WARNING, "ff_combine_frame failed\n"); |
| 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; |
| if (mp->bytes_left <= 0) { // prevent infinite loop |
| goto lost_sync; |
| } |
| 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) { |
| /* The first nibble of a frame is a parity check of the 4-byte |
| * access unit header and all the 2- or 4-byte substream headers. */ |
| // Only check when this isn't a sync frame - syncs have a checksum. |
| |
| parity_bits = 0; |
| for (i = -1; 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 { |
| GetBitContext gb; |
| MLPHeaderInfo mh; |
| |
| init_get_bits(&gb, buf + 4, (buf_size - 4) << 3); |
| if (ff_mlp_read_major_sync(avctx, &mh, &gb) < 0) |
| goto lost_sync; |
| |
| avctx->bits_per_raw_sample = mh.group1_bits; |
| if (avctx->bits_per_raw_sample > 16) |
| avctx->sample_fmt = AV_SAMPLE_FMT_S32; |
| else |
| avctx->sample_fmt = AV_SAMPLE_FMT_S16; |
| avctx->sample_rate = mh.group1_samplerate; |
| s->duration = mh.access_unit_size; |
| |
| if(!avctx->channels || !avctx->channel_layout) { |
| if (mh.stream_type == 0xbb) { |
| /* MLP stream */ |
| if (avctx->request_channel_layout && |
| (avctx->request_channel_layout & AV_CH_LAYOUT_STEREO) == |
| avctx->request_channel_layout && |
| mh.num_substreams > 1) { |
| avctx->channels = 2; |
| avctx->channel_layout = AV_CH_LAYOUT_STEREO; |
| } else { |
| avctx->channels = mh.channels_mlp; |
| avctx->channel_layout = mh.channel_layout_mlp; |
| } |
| } else { /* mh.stream_type == 0xba */ |
| /* TrueHD stream */ |
| if (avctx->request_channel_layout && |
| (avctx->request_channel_layout & AV_CH_LAYOUT_STEREO) == |
| avctx->request_channel_layout && |
| mh.num_substreams > 1) { |
| avctx->channels = 2; |
| avctx->channel_layout = AV_CH_LAYOUT_STEREO; |
| } else if (!mh.channels_thd_stream2 || |
| (avctx->request_channel_layout && |
| (avctx->request_channel_layout & mh.channel_layout_thd_stream1) == |
| avctx->request_channel_layout)) { |
| avctx->channels = mh.channels_thd_stream1; |
| avctx->channel_layout = mh.channel_layout_thd_stream1; |
| } else { |
| avctx->channels = mh.channels_thd_stream2; |
| avctx->channel_layout = mh.channel_layout_thd_stream2; |
| } |
| } |
| } |
| |
| 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 ff_mlp_parser = { |
| .codec_ids = { AV_CODEC_ID_MLP, AV_CODEC_ID_TRUEHD }, |
| .priv_data_size = sizeof(MLPParseContext), |
| .parser_init = mlp_init, |
| .parser_parse = mlp_parse, |
| .parser_close = ff_parse_close, |
| }; |
