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"
33 #include "mlp_parser.h"
36 static const uint8_t mlp_quants[16] = {
37 16, 20, 24, 0, 0, 0, 0, 0,
38 0, 0, 0, 0, 0, 0, 0, 0,
41 static const uint8_t mlp_channels[32] = {
42 1, 2, 3, 4, 3, 4, 5, 3, 4, 5, 4, 5, 6, 4, 5, 4,
43 5, 6, 5, 5, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
46 static const uint64_t mlp_layout[32] = {
51 AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY,
52 AV_CH_LAYOUT_2_1|AV_CH_LOW_FREQUENCY,
53 AV_CH_LAYOUT_2_2|AV_CH_LOW_FREQUENCY,
54 AV_CH_LAYOUT_SURROUND,
57 AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY,
58 AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY,
62 AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY,
63 AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY,
65 AV_CH_LAYOUT_2_2|AV_CH_LOW_FREQUENCY,
68 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
71 static const uint8_t thd_chancount[13] = {
72 // LR C LFE LRs LRvh LRc LRrs Cs Ts LRsd LRw Cvh LFE2
73 2, 1, 1, 2, 2, 2, 2, 1, 1, 2, 2, 1, 1
76 static const uint64_t thd_layout[13] = {
77 AV_CH_FRONT_LEFT|AV_CH_FRONT_RIGHT, // LR
78 AV_CH_FRONT_CENTER, // C
79 AV_CH_LOW_FREQUENCY, // LFE
80 AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT, // LRs
81 AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT, // LRvh
82 AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER, // LRc
83 AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT, // LRrs
84 AV_CH_BACK_CENTER, // Cs
85 AV_CH_TOP_CENTER, // Ts
86 AV_CH_SURROUND_DIRECT_LEFT|AV_CH_SURROUND_DIRECT_RIGHT, // LRsd
87 AV_CH_WIDE_LEFT|AV_CH_WIDE_RIGHT, // LRw
88 AV_CH_TOP_FRONT_CENTER, // Cvh
89 AV_CH_LOW_FREQUENCY_2, // LFE2
92 static int mlp_samplerate(int in)
97 return (in & 8 ? 44100 : 48000) << (in & 7) ;
100 static int truehd_channels(int chanmap)
104 for (i = 0; i < 13; i++)
105 channels += thd_chancount[i] * ((chanmap >> i) & 1);
110 static uint64_t truehd_layout(int chanmap)
115 for (i = 0; i < 13; i++)
116 layout |= thd_layout[i] * ((chanmap >> i) & 1);
121 /** Read a major sync info header - contains high level information about
122 * the stream - sample rate, channel arrangement etc. Most of this
123 * information is not actually necessary for decoding, only for playback.
124 * gb must be a freshly initialized GetBitContext with no bits read.
127 int ff_mlp_read_major_sync(void *log, MLPHeaderInfo *mh, GetBitContext *gb)
129 int ratebits, channel_arrangement;
132 assert(get_bits_count(gb) == 0);
134 if (gb->size_in_bits < 28 << 3) {
135 av_log(log, AV_LOG_ERROR, "packet too short, unable to read major sync\n");
139 checksum = ff_mlp_checksum16(gb->buffer, 26);
140 if (checksum != AV_RL16(gb->buffer+26)) {
141 av_log(log, AV_LOG_ERROR, "major sync info header checksum error\n");
142 return AVERROR_INVALIDDATA;
145 if (get_bits_long(gb, 24) != 0xf8726f) /* Sync words */
146 return AVERROR_INVALIDDATA;
148 mh->stream_type = get_bits(gb, 8);
150 if (mh->stream_type == 0xbb) {
151 mh->group1_bits = mlp_quants[get_bits(gb, 4)];
152 mh->group2_bits = mlp_quants[get_bits(gb, 4)];
154 ratebits = get_bits(gb, 4);
155 mh->group1_samplerate = mlp_samplerate(ratebits);
156 mh->group2_samplerate = mlp_samplerate(get_bits(gb, 4));
160 channel_arrangement = get_bits(gb, 5);
161 mh->channels_mlp = mlp_channels[channel_arrangement];
162 mh->channel_layout_mlp = mlp_layout[channel_arrangement];
163 } else if (mh->stream_type == 0xba) {
164 mh->group1_bits = 24; // TODO: Is this information actually conveyed anywhere?
167 ratebits = get_bits(gb, 4);
168 mh->group1_samplerate = mlp_samplerate(ratebits);
169 mh->group2_samplerate = 0;
173 channel_arrangement = get_bits(gb, 5);
174 mh->channels_thd_stream1 = truehd_channels(channel_arrangement);
175 mh->channel_layout_thd_stream1 = truehd_layout(channel_arrangement);
179 channel_arrangement = get_bits(gb, 13);
180 mh->channels_thd_stream2 = truehd_channels(channel_arrangement);
181 mh->channel_layout_thd_stream2 = truehd_layout(channel_arrangement);
183 return AVERROR_INVALIDDATA;
185 mh->access_unit_size = 40 << (ratebits & 7);
186 mh->access_unit_size_pow2 = 64 << (ratebits & 7);
188 skip_bits_long(gb, 48);
190 mh->is_vbr = get_bits1(gb);
192 mh->peak_bitrate = (get_bits(gb, 15) * mh->group1_samplerate + 8) >> 4;
194 mh->num_substreams = get_bits(gb, 4);
196 skip_bits_long(gb, 4 + 11 * 8);
201 typedef struct MLPParseContext
212 static av_cold int mlp_init(AVCodecParserContext *s)
218 static int mlp_parse(AVCodecParserContext *s,
219 AVCodecContext *avctx,
220 const uint8_t **poutbuf, int *poutbuf_size,
221 const uint8_t *buf, int buf_size)
223 MLPParseContext *mp = s->priv_data;
234 // Not in sync - find a major sync header
236 for (i = 0; i < buf_size; i++) {
237 mp->pc.state = (mp->pc.state << 8) | buf[i];
238 if ((mp->pc.state & 0xfffffffe) == 0xf8726fba &&
239 // ignore if we do not have the data for the start of header
240 mp->pc.index + i >= 7) {
248 ff_combine_frame(&mp->pc, END_NOT_FOUND, &buf, &buf_size);
252 ff_combine_frame(&mp->pc, i - 7, &buf, &buf_size);
257 if (mp->bytes_left == 0) {
258 // Find length of this packet
260 /* Copy overread bytes from last frame into buffer. */
261 for(; mp->pc.overread>0; mp->pc.overread--) {
262 mp->pc.buffer[mp->pc.index++]= mp->pc.buffer[mp->pc.overread_index++];
265 if (mp->pc.index + buf_size < 2) {
266 ff_combine_frame(&mp->pc, END_NOT_FOUND, &buf, &buf_size);
270 mp->bytes_left = ((mp->pc.index > 0 ? mp->pc.buffer[0] : buf[0]) << 8)
271 | (mp->pc.index > 1 ? mp->pc.buffer[1] : buf[1-mp->pc.index]);
272 mp->bytes_left = (mp->bytes_left & 0xfff) * 2;
273 mp->bytes_left -= mp->pc.index;
276 next = (mp->bytes_left > buf_size) ? END_NOT_FOUND : mp->bytes_left;
278 if (ff_combine_frame(&mp->pc, next, &buf, &buf_size) < 0) {
279 mp->bytes_left -= buf_size;
285 sync_present = (AV_RB32(buf + 4) & 0xfffffffe) == 0xf8726fba;
288 /* The first nibble of a frame is a parity check of the 4-byte
289 * access unit header and all the 2- or 4-byte substream headers. */
290 // Only check when this isn't a sync frame - syncs have a checksum.
293 for (i = -1; i < mp->num_substreams; i++) {
294 parity_bits ^= buf[p++];
295 parity_bits ^= buf[p++];
297 if (i < 0 || buf[p-2] & 0x80) {
298 parity_bits ^= buf[p++];
299 parity_bits ^= buf[p++];
303 if ((((parity_bits >> 4) ^ parity_bits) & 0xF) != 0xF) {
304 av_log(avctx, AV_LOG_INFO, "mlpparse: Parity check failed.\n");
311 init_get_bits(&gb, buf + 4, (buf_size - 4) << 3);
312 if (ff_mlp_read_major_sync(avctx, &mh, &gb) < 0)
315 avctx->bits_per_raw_sample = mh.group1_bits;
316 if (avctx->bits_per_raw_sample > 16)
317 avctx->sample_fmt = AV_SAMPLE_FMT_S32;
319 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
320 avctx->sample_rate = mh.group1_samplerate;
321 s->duration = mh.access_unit_size;
323 if (mh.stream_type == 0xbb) {
325 #if FF_API_REQUEST_CHANNELS
326 if (avctx->request_channels > 0 && avctx->request_channels <= 2 &&
327 mh.num_substreams > 1) {
329 avctx->channel_layout = AV_CH_LAYOUT_STEREO;
332 if (avctx->request_channel_layout == AV_CH_LAYOUT_STEREO &&
333 mh.num_substreams > 1) {
335 avctx->channel_layout = AV_CH_LAYOUT_STEREO;
337 avctx->channels = mh.channels_mlp;
338 avctx->channel_layout = mh.channel_layout_mlp;
340 } else { /* mh.stream_type == 0xba */
342 #if FF_API_REQUEST_CHANNELS
343 if (avctx->request_channels > 0 && avctx->request_channels <= 2 &&
344 mh.num_substreams > 1) {
346 avctx->channel_layout = AV_CH_LAYOUT_STEREO;
347 } else if (avctx->request_channels > 0 &&
348 avctx->request_channels <= mh.channels_thd_stream1) {
349 avctx->channels = mh.channels_thd_stream1;
350 avctx->channel_layout = mh.channel_layout_thd_stream1;
353 if (avctx->request_channel_layout == AV_CH_LAYOUT_STEREO &&
354 mh.num_substreams > 1) {
356 avctx->channel_layout = AV_CH_LAYOUT_STEREO;
357 } else if (avctx->request_channel_layout == mh.channel_layout_thd_stream1 ||
358 !mh.channels_thd_stream2) {
359 avctx->channels = mh.channels_thd_stream1;
360 avctx->channel_layout = mh.channel_layout_thd_stream1;
362 avctx->channels = mh.channels_thd_stream2;
363 avctx->channel_layout = mh.channel_layout_thd_stream2;
367 if (!mh.is_vbr) /* Stream is CBR */
368 avctx->bit_rate = mh.peak_bitrate;
370 mp->num_substreams = mh.num_substreams;
374 *poutbuf_size = buf_size;
383 AVCodecParser ff_mlp_parser = {
384 .codec_ids = { AV_CODEC_ID_MLP, AV_CODEC_ID_TRUEHD },
385 .priv_data_size = sizeof(MLPParseContext),
386 .parser_init = mlp_init,
387 .parser_parse = mlp_parse,
388 .parser_close = ff_parse_close,