3 * Copyright (c) 2007 Ian Caulfield
5 * This file is part of Libav.
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
29 #include "libavutil/channel_layout.h"
30 #include "libavutil/crc.h"
31 #include "libavutil/internal.h"
34 #include "mlp_parser.h"
37 static const uint8_t mlp_quants[16] = {
38 16, 20, 24, 0, 0, 0, 0, 0,
39 0, 0, 0, 0, 0, 0, 0, 0,
42 static const uint8_t mlp_channels[32] = {
43 1, 2, 3, 4, 3, 4, 5, 3, 4, 5, 4, 5, 6, 4, 5, 4,
44 5, 6, 5, 5, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
47 static const uint64_t mlp_layout[32] = {
52 AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY,
53 AV_CH_LAYOUT_2_1|AV_CH_LOW_FREQUENCY,
54 AV_CH_LAYOUT_2_2|AV_CH_LOW_FREQUENCY,
55 AV_CH_LAYOUT_SURROUND,
58 AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY,
59 AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY,
63 AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY,
64 AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY,
66 AV_CH_LAYOUT_2_2|AV_CH_LOW_FREQUENCY,
69 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
72 static const uint8_t thd_chancount[13] = {
73 // LR C LFE LRs LRvh LRc LRrs Cs Ts LRsd LRw Cvh LFE2
74 2, 1, 1, 2, 2, 2, 2, 1, 1, 2, 2, 1, 1
77 static const uint64_t thd_layout[13] = {
78 AV_CH_FRONT_LEFT|AV_CH_FRONT_RIGHT, // LR
79 AV_CH_FRONT_CENTER, // C
80 AV_CH_LOW_FREQUENCY, // LFE
81 AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT, // LRs
82 AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT, // LRvh
83 AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER, // LRc
84 AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT, // LRrs
85 AV_CH_BACK_CENTER, // Cs
86 AV_CH_TOP_CENTER, // Ts
87 AV_CH_SURROUND_DIRECT_LEFT|AV_CH_SURROUND_DIRECT_RIGHT, // LRsd
88 AV_CH_WIDE_LEFT|AV_CH_WIDE_RIGHT, // LRw
89 AV_CH_TOP_FRONT_CENTER, // Cvh
90 AV_CH_LOW_FREQUENCY_2, // LFE2
93 static int mlp_samplerate(int in)
98 return (in & 8 ? 44100 : 48000) << (in & 7) ;
101 static int truehd_channels(int chanmap)
105 for (i = 0; i < 13; i++)
106 channels += thd_chancount[i] * ((chanmap >> i) & 1);
111 static uint64_t truehd_layout(int chanmap)
116 for (i = 0; i < 13; i++)
117 layout |= thd_layout[i] * ((chanmap >> i) & 1);
122 /** Read a major sync info header - contains high level information about
123 * the stream - sample rate, channel arrangement etc. Most of this
124 * information is not actually necessary for decoding, only for playback.
125 * gb must be a freshly initialized GetBitContext with no bits read.
128 int ff_mlp_read_major_sync(void *log, MLPHeaderInfo *mh, GetBitContext *gb)
130 int ratebits, channel_arrangement;
133 assert(get_bits_count(gb) == 0);
135 if (gb->size_in_bits < 28 << 3) {
136 av_log(log, AV_LOG_ERROR, "packet too short, unable to read major sync\n");
140 checksum = ff_mlp_checksum16(gb->buffer, 26);
141 if (checksum != AV_RL16(gb->buffer+26)) {
142 av_log(log, AV_LOG_ERROR, "major sync info header checksum error\n");
143 return AVERROR_INVALIDDATA;
146 if (get_bits_long(gb, 24) != 0xf8726f) /* Sync words */
147 return AVERROR_INVALIDDATA;
149 mh->stream_type = get_bits(gb, 8);
151 if (mh->stream_type == 0xbb) {
152 mh->group1_bits = mlp_quants[get_bits(gb, 4)];
153 mh->group2_bits = mlp_quants[get_bits(gb, 4)];
155 ratebits = get_bits(gb, 4);
156 mh->group1_samplerate = mlp_samplerate(ratebits);
157 mh->group2_samplerate = mlp_samplerate(get_bits(gb, 4));
161 channel_arrangement = get_bits(gb, 5);
162 mh->channels_mlp = mlp_channels[channel_arrangement];
163 mh->channel_layout_mlp = mlp_layout[channel_arrangement];
164 } else if (mh->stream_type == 0xba) {
165 mh->group1_bits = 24; // TODO: Is this information actually conveyed anywhere?
168 ratebits = get_bits(gb, 4);
169 mh->group1_samplerate = mlp_samplerate(ratebits);
170 mh->group2_samplerate = 0;
174 mh->channel_modifier_thd_stream0 = get_bits(gb, 2);
175 mh->channel_modifier_thd_stream1 = get_bits(gb, 2);
177 channel_arrangement = get_bits(gb, 5);
178 mh->channels_thd_stream1 = truehd_channels(channel_arrangement);
179 mh->channel_layout_thd_stream1 = truehd_layout(channel_arrangement);
181 mh->channel_modifier_thd_stream2 = get_bits(gb, 2);
183 channel_arrangement = get_bits(gb, 13);
184 mh->channels_thd_stream2 = truehd_channels(channel_arrangement);
185 mh->channel_layout_thd_stream2 = truehd_layout(channel_arrangement);
187 return AVERROR_INVALIDDATA;
189 mh->access_unit_size = 40 << (ratebits & 7);
190 mh->access_unit_size_pow2 = 64 << (ratebits & 7);
192 skip_bits_long(gb, 48);
194 mh->is_vbr = get_bits1(gb);
196 mh->peak_bitrate = (get_bits(gb, 15) * mh->group1_samplerate + 8) >> 4;
198 mh->num_substreams = get_bits(gb, 4);
200 skip_bits_long(gb, 4 + 11 * 8);
205 typedef struct MLPParseContext
216 static av_cold int mlp_init(AVCodecParserContext *s)
222 static int mlp_parse(AVCodecParserContext *s,
223 AVCodecContext *avctx,
224 const uint8_t **poutbuf, int *poutbuf_size,
225 const uint8_t *buf, int buf_size)
227 MLPParseContext *mp = s->priv_data;
238 // Not in sync - find a major sync header
240 for (i = 0; i < buf_size; i++) {
241 mp->pc.state = (mp->pc.state << 8) | buf[i];
242 if ((mp->pc.state & 0xfffffffe) == 0xf8726fba &&
243 // ignore if we do not have the data for the start of header
244 mp->pc.index + i >= 7) {
252 ff_combine_frame(&mp->pc, END_NOT_FOUND, &buf, &buf_size);
256 ff_combine_frame(&mp->pc, i - 7, &buf, &buf_size);
261 if (mp->bytes_left == 0) {
262 // Find length of this packet
264 /* Copy overread bytes from last frame into buffer. */
265 for(; mp->pc.overread>0; mp->pc.overread--) {
266 mp->pc.buffer[mp->pc.index++]= mp->pc.buffer[mp->pc.overread_index++];
269 if (mp->pc.index + buf_size < 2) {
270 ff_combine_frame(&mp->pc, END_NOT_FOUND, &buf, &buf_size);
274 mp->bytes_left = ((mp->pc.index > 0 ? mp->pc.buffer[0] : buf[0]) << 8)
275 | (mp->pc.index > 1 ? mp->pc.buffer[1] : buf[1-mp->pc.index]);
276 mp->bytes_left = (mp->bytes_left & 0xfff) * 2;
277 mp->bytes_left -= mp->pc.index;
280 next = (mp->bytes_left > buf_size) ? END_NOT_FOUND : mp->bytes_left;
282 if (ff_combine_frame(&mp->pc, next, &buf, &buf_size) < 0) {
283 mp->bytes_left -= buf_size;
289 sync_present = (AV_RB32(buf + 4) & 0xfffffffe) == 0xf8726fba;
292 /* The first nibble of a frame is a parity check of the 4-byte
293 * access unit header and all the 2- or 4-byte substream headers. */
294 // Only check when this isn't a sync frame - syncs have a checksum.
297 for (i = -1; i < mp->num_substreams; i++) {
298 parity_bits ^= buf[p++];
299 parity_bits ^= buf[p++];
301 if (i < 0 || buf[p-2] & 0x80) {
302 parity_bits ^= buf[p++];
303 parity_bits ^= buf[p++];
307 if ((((parity_bits >> 4) ^ parity_bits) & 0xF) != 0xF) {
308 av_log(avctx, AV_LOG_INFO, "mlpparse: Parity check failed.\n");
315 init_get_bits(&gb, buf + 4, (buf_size - 4) << 3);
316 if (ff_mlp_read_major_sync(avctx, &mh, &gb) < 0)
319 avctx->bits_per_raw_sample = mh.group1_bits;
320 if (avctx->bits_per_raw_sample > 16)
321 avctx->sample_fmt = AV_SAMPLE_FMT_S32;
323 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
324 avctx->sample_rate = mh.group1_samplerate;
325 s->duration = mh.access_unit_size;
327 if (mh.stream_type == 0xbb) {
329 #if FF_API_REQUEST_CHANNELS
330 FF_DISABLE_DEPRECATION_WARNINGS
331 if (avctx->request_channels > 0 && avctx->request_channels <= 2 &&
332 mh.num_substreams > 1) {
334 avctx->channel_layout = AV_CH_LAYOUT_STEREO;
336 FF_ENABLE_DEPRECATION_WARNINGS
338 if (avctx->request_channel_layout &&
339 (avctx->request_channel_layout & AV_CH_LAYOUT_STEREO) ==
340 avctx->request_channel_layout &&
341 mh.num_substreams > 1) {
343 avctx->channel_layout = AV_CH_LAYOUT_STEREO;
345 avctx->channels = mh.channels_mlp;
346 avctx->channel_layout = mh.channel_layout_mlp;
348 } else { /* mh.stream_type == 0xba */
350 #if FF_API_REQUEST_CHANNELS
351 FF_DISABLE_DEPRECATION_WARNINGS
352 if (avctx->request_channels > 0 && avctx->request_channels <= 2 &&
353 mh.num_substreams > 1) {
355 avctx->channel_layout = AV_CH_LAYOUT_STEREO;
356 } else if (avctx->request_channels > 0 &&
357 avctx->request_channels <= mh.channels_thd_stream1) {
358 avctx->channels = mh.channels_thd_stream1;
359 avctx->channel_layout = mh.channel_layout_thd_stream1;
361 FF_ENABLE_DEPRECATION_WARNINGS
363 if (avctx->request_channel_layout &&
364 (avctx->request_channel_layout & AV_CH_LAYOUT_STEREO) ==
365 avctx->request_channel_layout &&
366 mh.num_substreams > 1) {
368 avctx->channel_layout = AV_CH_LAYOUT_STEREO;
369 } else if (!mh.channels_thd_stream2 ||
370 (avctx->request_channel_layout &&
371 (avctx->request_channel_layout & mh.channel_layout_thd_stream1) ==
372 avctx->request_channel_layout)) {
373 avctx->channels = mh.channels_thd_stream1;
374 avctx->channel_layout = mh.channel_layout_thd_stream1;
376 avctx->channels = mh.channels_thd_stream2;
377 avctx->channel_layout = mh.channel_layout_thd_stream2;
381 if (!mh.is_vbr) /* Stream is CBR */
382 avctx->bit_rate = mh.peak_bitrate;
384 mp->num_substreams = mh.num_substreams;
388 *poutbuf_size = buf_size;
397 AVCodecParser ff_mlp_parser = {
398 .codec_ids = { AV_CODEC_ID_MLP, AV_CODEC_ID_TRUEHD },
399 .priv_data_size = sizeof(MLPParseContext),
400 .parser_init = mlp_init,
401 .parser_parse = mlp_parse,
402 .parser_close = ff_parse_close,