/* * 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 */ #include <stdint.h> #include "libavutil/channel_layout.h" #include "get_bits.h" #include "mlp_parse.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, }; static const uint64_t 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 int 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 = 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(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 = 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 = 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 = 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(gb, 2); mh->extended_substream_info = get_bits(gb, 2); mh->substream_info = get_bits(gb, 8); skip_bits_long(gb, (header_size - 18) * 8); return 0; }