| /* |
| * 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_long(gb, 4 + (header_size - 17) * 8); |
| |
| return 0; |
| } |