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FFmpeg/libavformat/riffdec.c
2013-08-06 11:02:36 +02:00

230 lines
7.5 KiB
C

/*
* RIFF demuxing functions and data
* Copyright (c) 2000 Fabrice Bellard
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/dict.h"
#include "libavutil/error.h"
#include "libavutil/log.h"
#include "libavutil/mathematics.h"
#include "libavcodec/avcodec.h"
#include "libavcodec/bytestream.h"
#include "avformat.h"
#include "avio_internal.h"
#include "riff.h"
const AVCodecGuid ff_codec_wav_guids[] = {
{ AV_CODEC_ID_AC3, { 0x2C, 0x80, 0x6D, 0xE0, 0x46, 0xDB, 0xCF, 0x11, 0xB4, 0xD1, 0x00, 0x80, 0x5F, 0x6C, 0xBB, 0xEA } },
{ AV_CODEC_ID_ATRAC3P, { 0xBF, 0xAA, 0x23, 0xE9, 0x58, 0xCB, 0x71, 0x44, 0xA1, 0x19, 0xFF, 0xFA, 0x01, 0xE4, 0xCE, 0x62 } },
{ AV_CODEC_ID_EAC3, { 0xAF, 0x87, 0xFB, 0xA7, 0x02, 0x2D, 0xFB, 0x42, 0xA4, 0xD4, 0x05, 0xCD, 0x93, 0x84, 0x3B, 0xDD } },
{ AV_CODEC_ID_MP2, { 0x2B, 0x80, 0x6D, 0xE0, 0x46, 0xDB, 0xCF, 0x11, 0xB4, 0xD1, 0x00, 0x80, 0x5F, 0x6C, 0xBB, 0xEA } },
{ AV_CODEC_ID_NONE }
};
enum AVCodecID ff_codec_guid_get_id(const AVCodecGuid *guids, ff_asf_guid guid)
{
int i;
for (i = 0; guids[i].id != AV_CODEC_ID_NONE; i++)
if (!ff_guidcmp(guids[i].guid, guid))
return guids[i].id;
return AV_CODEC_ID_NONE;
}
/* We could be given one of the three possible structures here:
* WAVEFORMAT, PCMWAVEFORMAT or WAVEFORMATEX. Each structure
* is an expansion of the previous one with the fields added
* at the bottom. PCMWAVEFORMAT adds 'WORD wBitsPerSample' and
* WAVEFORMATEX adds 'WORD cbSize' and basically makes itself
* an openended structure.
*/
static void parse_waveformatex(AVIOContext *pb, AVCodecContext *c)
{
ff_asf_guid subformat;
c->bits_per_coded_sample = avio_rl16(pb);
c->channel_layout = avio_rl32(pb); /* dwChannelMask */
ff_get_guid(pb, &subformat);
if (!memcmp(subformat + 4,
(const uint8_t[]){ FF_MEDIASUBTYPE_BASE_GUID }, 12)) {
c->codec_tag = AV_RL32(subformat);
c->codec_id = ff_wav_codec_get_id(c->codec_tag,
c->bits_per_coded_sample);
} else {
c->codec_id = ff_codec_guid_get_id(ff_codec_wav_guids, subformat);
if (!c->codec_id)
av_log(c, AV_LOG_WARNING,
"unknown subformat:"FF_PRI_GUID"\n",
FF_ARG_GUID(subformat));
}
}
int ff_get_wav_header(AVIOContext *pb, AVCodecContext *codec, int size)
{
int id;
id = avio_rl16(pb);
codec->codec_type = AVMEDIA_TYPE_AUDIO;
codec->channels = avio_rl16(pb);
codec->sample_rate = avio_rl32(pb);
codec->bit_rate = avio_rl32(pb) * 8;
codec->block_align = avio_rl16(pb);
if (size == 14) { /* We're dealing with plain vanilla WAVEFORMAT */
codec->bits_per_coded_sample = 8;
} else
codec->bits_per_coded_sample = avio_rl16(pb);
if (id == 0xFFFE) {
codec->codec_tag = 0;
} else {
codec->codec_tag = id;
codec->codec_id = ff_wav_codec_get_id(id,
codec->bits_per_coded_sample);
}
if (size >= 18) { /* We're obviously dealing with WAVEFORMATEX */
int cbSize = avio_rl16(pb); /* cbSize */
size -= 18;
cbSize = FFMIN(size, cbSize);
if (cbSize >= 22 && id == 0xfffe) { /* WAVEFORMATEXTENSIBLE */
parse_waveformatex(pb, codec);
cbSize -= 22;
size -= 22;
}
codec->extradata_size = cbSize;
if (cbSize > 0) {
av_free(codec->extradata);
codec->extradata = av_mallocz(codec->extradata_size +
FF_INPUT_BUFFER_PADDING_SIZE);
if (!codec->extradata)
return AVERROR(ENOMEM);
avio_read(pb, codec->extradata, codec->extradata_size);
size -= cbSize;
}
/* It is possible for the chunk to contain garbage at the end */
if (size > 0)
avio_skip(pb, size);
}
if (codec->codec_id == AV_CODEC_ID_AAC_LATM) {
/* Channels and sample_rate values are those prior to applying SBR
* and/or PS. */
codec->channels = 0;
codec->sample_rate = 0;
}
/* override bits_per_coded_sample for G.726 */
if (codec->codec_id == AV_CODEC_ID_ADPCM_G726)
codec->bits_per_coded_sample = codec->bit_rate / codec->sample_rate;
return 0;
}
enum AVCodecID ff_wav_codec_get_id(unsigned int tag, int bps)
{
enum AVCodecID id;
id = ff_codec_get_id(ff_codec_wav_tags, tag);
if (id <= 0)
return id;
if (id == AV_CODEC_ID_PCM_S16LE)
id = ff_get_pcm_codec_id(bps, 0, 0, ~1);
else if (id == AV_CODEC_ID_PCM_F32LE)
id = ff_get_pcm_codec_id(bps, 1, 0, 0);
if (id == AV_CODEC_ID_ADPCM_IMA_WAV && bps == 8)
id = AV_CODEC_ID_PCM_ZORK;
return id;
}
int ff_get_bmp_header(AVIOContext *pb, AVStream *st)
{
int tag1;
avio_rl32(pb); /* size */
st->codec->width = avio_rl32(pb);
st->codec->height = (int32_t)avio_rl32(pb);
avio_rl16(pb); /* planes */
st->codec->bits_per_coded_sample = avio_rl16(pb); /* depth */
tag1 = avio_rl32(pb);
avio_rl32(pb); /* ImageSize */
avio_rl32(pb); /* XPelsPerMeter */
avio_rl32(pb); /* YPelsPerMeter */
avio_rl32(pb); /* ClrUsed */
avio_rl32(pb); /* ClrImportant */
return tag1;
}
int ff_read_riff_info(AVFormatContext *s, int64_t size)
{
int64_t start, end, cur;
AVIOContext *pb = s->pb;
start = avio_tell(pb);
end = start + size;
while ((cur = avio_tell(pb)) >= 0 &&
cur <= end - 8 /* = tag + size */) {
uint32_t chunk_code;
int64_t chunk_size;
char key[5] = { 0 };
char *value;
chunk_code = avio_rl32(pb);
chunk_size = avio_rl32(pb);
if (chunk_size > end ||
end - chunk_size < cur ||
chunk_size == UINT_MAX) {
av_log(s, AV_LOG_WARNING, "too big INFO subchunk\n");
break;
}
chunk_size += (chunk_size & 1);
if (!chunk_code) {
if (chunk_size)
avio_skip(pb, chunk_size);
else if (pb->eof_reached) {
av_log(s, AV_LOG_WARNING, "truncated file\n");
return AVERROR_EOF;
}
continue;
}
value = av_malloc(chunk_size + 1);
if (!value) {
av_log(s, AV_LOG_ERROR,
"out of memory, unable to read INFO tag\n");
return AVERROR(ENOMEM);
}
AV_WL32(key, chunk_code);
if (avio_read(pb, value, chunk_size) != chunk_size) {
av_free(value);
av_log(s, AV_LOG_WARNING,
"premature end of file while reading INFO tag\n");
break;
}
value[chunk_size] = 0;
av_dict_set(&s->metadata, key, value, AV_DICT_DONT_STRDUP_VAL);
}
return 0;
}