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FFmpeg/libavcodec/mlp_parser.c
Michael Niedermayer 1caa4123bd Merge remote-tracking branch 'newdev/master' 
* newdev/master:
  rtsp: Use GET_PARAMETER for keep-alive for generic RTSP servers
  mlp_parse.c: set AVCodecContext channel_layout
  APIChanges: mark the place where 0.6 was branched.
  avio: make get_checksum() internal.
  avio: move ff_crc04C11DB7_update() from avio.h -> avio_internal.h
  avio: make init_checksum() internal.
NOT MERGED  Add MxPEG decoder
NOT MERGED  Add support for picture_ptr field in MJpegDecodeContext
NOT MERGED  Move MJPEG's input buffer preprocessing in separate public function
NOT MERGED  Support reference picture defined by bitmask in MJPEG's SOS decoder
  sndio bug fix

Merged-by: Michael Niedermayer <michaelni@gmx.at>
2011-03-31 12:48:41 +02:00

353 lines
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C
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/*
* 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/crc.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,
};
static const uint64_t mlp_layout[32] = {
AV_CH_LAYOUT_MONO,
AV_CH_LAYOUT_STEREO,
AV_CH_LAYOUT_2_1,
AV_CH_LAYOUT_2_2,
AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_2_1|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_2_2|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_SURROUND,
AV_CH_LAYOUT_4POINT0,
AV_CH_LAYOUT_5POINT0,
AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_5POINT1,
AV_CH_LAYOUT_4POINT0,
AV_CH_LAYOUT_5POINT0,
AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_5POINT1,
AV_CH_LAYOUT_2_2|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_5POINT0,
AV_CH_LAYOUT_5POINT1,
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_SIDE_LEFT|AV_CH_SIDE_RIGHT, // LRc
AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT, // LRrs
AV_CH_BACK_CENTER, // Cs
AV_CH_TOP_BACK_CENTER, // Ts
AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT, // LRsd
AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER, // LRw
AV_CH_TOP_BACK_CENTER, // Cvh
AV_CH_LOW_FREQUENCY // 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;
}
static int64_t truehd_layout(int chanmap)
{
int layout = 0, i;
for (i = 0; i < 13; i++)
layout |= thd_layout[i] * ((chanmap >> i) & 1);
return layout;
}
/** 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;
uint16_t checksum;
assert(get_bits_count(gb) == 0);
if (gb->size_in_bits < 28 << 3) {
av_log(log, AV_LOG_ERROR, "packet too short, unable to read major sync\n");
return -1;
}
checksum = ff_mlp_checksum16(gb->buffer, 26);
if (checksum != AV_RL16(gb->buffer+26)) {
av_log(log, AV_LOG_ERROR, "major sync info header checksum error\n");
return -1;
}
if (get_bits_long(gb, 24) != 0xf8726f) /* Sync words */
return -1;
mh->stream_type = get_bits(gb, 8);
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->channels_mlp = get_bits(gb, 5);
} 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, 8);
mh->channels_thd_stream1 = get_bits(gb, 5);
skip_bits(gb, 2);
mh->channels_thd_stream2 = get_bits(gb, 13);
} else
return -1;
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 + 11 * 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 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) {
ff_combine_frame(&mp->pc, END_NOT_FOUND, &buf, &buf_size);
return buf_size;
}
ff_combine_frame(&mp->pc, i - 7, &buf, &buf_size);
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) {
ff_combine_frame(&mp->pc, END_NOT_FOUND, &buf, &buf_size);
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;
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;
avctx->frame_size = mh.access_unit_size;
if (mh.stream_type == 0xbb) {
/* MLP stream */
avctx->channels = mlp_channels[mh.channels_mlp];
avctx->channel_layout = mlp_layout[mh.channels_mlp];
} else { /* mh.stream_type == 0xba */
/* TrueHD stream */
if (mh.channels_thd_stream2) {
avctx->channels = truehd_channels(mh.channels_thd_stream2);
avctx->channel_layout = truehd_layout(mh.channels_thd_stream2);
} else {
avctx->channels = truehd_channels(mh.channels_thd_stream1);
avctx->channel_layout = truehd_layout(mh.channels_thd_stream1);
}
}
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_ID_MLP, CODEC_ID_TRUEHD },
sizeof(MLPParseContext),
mlp_init,
mlp_parse,
ff_parse_close,
};
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