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Code Issues Releases Activity

avformat/apm: read header correctly

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The leading WAVEFORMATEX in .APM files is malformed:
* The nAvgBytesPerSec field is wrong, and
* sizeof(cbSize) is 4 instead of 2.
This commit is contained in:
Zane van Iperen 2020-06-30 10:44:39 +10:00
parent 68c56082d3
commit 3bf1be2101
2 changed files with 35 additions and 21 deletions
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2
libavformat/Makefile
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@ -93,7 +93,7 @@ OBJS-$(CONFIG_AMRWB_DEMUXER) += amr.o
OBJS-$(CONFIG_ANM_DEMUXER) += anm.o
OBJS-$(CONFIG_APC_DEMUXER) += apc.o
OBJS-$(CONFIG_APE_DEMUXER) += ape.o apetag.o img2.o
OBJS-$(CONFIG_APM_DEMUXER) += apm.o riffdec.o
OBJS-$(CONFIG_APM_DEMUXER) += apm.o
OBJS-$(CONFIG_APNG_DEMUXER) += apngdec.o
OBJS-$(CONFIG_APNG_MUXER) += apngenc.o
OBJS-$(CONFIG_APTX_DEMUXER) += aptxdec.o rawdec.o

54
libavformat/apm.c
View File

@ -21,12 +21,12 @@
*/
#include "avformat.h"
#include "internal.h"
#include "riff.h"
#include "libavutil/internal.h"
#include "libavutil/intreadwrite.h"
#define APM_FILE_HEADER_SIZE 20
#define APM_VS12_CHUNK_SIZE 76
#define APM_FILE_HEADER_SIZE 18
#define APM_FILE_EXTRADATA_SIZE 80
#define APM_MAX_READ_SIZE 4096
#define APM_TAG_CODEC 0x2000
@ -51,6 +51,7 @@ typedef struct APMVS12Chunk {
uint32_t unk2;
APMState state;
uint32_t pad[7];
uint32_t data;
} APMVS12Chunk;
static void apm_parse_vs12(APMVS12Chunk *vs12, const uint8_t *buf)
@ -71,6 +72,8 @@ static void apm_parse_vs12(APMVS12Chunk *vs12, const uint8_t *buf)
for (int i = 0; i < FF_ARRAY_ELEMS(vs12->pad); i++)
vs12->pad[i] = AV_RL32(buf + 48 + (i * 4));
vs12->data = AV_RL32(buf + 76);
}
static int apm_probe(const AVProbeData *p)
@ -95,25 +98,38 @@ static int apm_read_header(AVFormatContext *s)
int64_t ret;
AVStream *st;
APMVS12Chunk vs12;
uint8_t buf[APM_VS12_CHUNK_SIZE];
uint8_t buf[APM_FILE_EXTRADATA_SIZE];
if (!(st = avformat_new_stream(s, NULL)))
return AVERROR(ENOMEM);
/* The header starts with a WAVEFORMATEX */
if ((ret = ff_get_wav_header(s, s->pb, st->codecpar, APM_FILE_HEADER_SIZE, 0)) < 0)
/*
* This is 98% a WAVEFORMATEX, but there's something screwy with the extradata
* that ff_get_wav_header() can't (and shouldn't) handle properly.
*/
if (avio_rl16(s->pb) != APM_TAG_CODEC)
return AVERROR_INVALIDDATA;
st->codecpar->channels = avio_rl16(s->pb);
st->codecpar->sample_rate = avio_rl32(s->pb);
/* Skip the bitrate, it's usually wrong anyway. */
if ((ret = avio_skip(s->pb, 4)) < 0)
return ret;
st->codecpar->block_align = avio_rl16(s->pb);
st->codecpar->bits_per_coded_sample = avio_rl16(s->pb);
if (avio_rl32(s->pb) != APM_FILE_EXTRADATA_SIZE)
return AVERROR_INVALIDDATA;
/* I've never seen files greater than this. */
if (st->codecpar->sample_rate > 44100)
return AVERROR_INVALIDDATA;
if (st->codecpar->bits_per_coded_sample != 4)
return AVERROR_INVALIDDATA;
if (st->codecpar->codec_tag != APM_TAG_CODEC)
return AVERROR_INVALIDDATA;
/* ff_get_wav_header() does most of the work, but we need to fix a few things. */
st->codecpar->codec_id = AV_CODEC_ID_ADPCM_IMA_APM;
st->codecpar->codec_tag = 0;
if (st->codecpar->channels == 2)
st->codecpar->channel_layout = AV_CH_LAYOUT_STEREO;
else if (st->codecpar->channels == 1)
@ -121,31 +137,29 @@ static int apm_read_header(AVFormatContext *s)
else
return AVERROR_INVALIDDATA;
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_id = AV_CODEC_ID_ADPCM_IMA_APM;
st->codecpar->format = AV_SAMPLE_FMT_S16;
st->codecpar->bits_per_raw_sample = 16;
st->codecpar->bit_rate = st->codecpar->channels *
st->codecpar->sample_rate *
st->codecpar->bits_per_coded_sample;
if ((ret = avio_read(s->pb, buf, APM_VS12_CHUNK_SIZE)) < 0)
if ((ret = avio_read(s->pb, buf, APM_FILE_EXTRADATA_SIZE)) < 0)
return ret;
else if (ret != APM_VS12_CHUNK_SIZE)
else if (ret != APM_FILE_EXTRADATA_SIZE)
return AVERROR(EIO);
apm_parse_vs12(&vs12, buf);
if (vs12.magic != APM_TAG_VS12) {
if (vs12.magic != APM_TAG_VS12 || vs12.data != APM_TAG_DATA)
return AVERROR_INVALIDDATA;
}
if (vs12.state.has_saved) {
avpriv_request_sample(s, "Saved Samples");
return AVERROR_PATCHWELCOME;
}
if (avio_rl32(s->pb) != APM_TAG_DATA)
return AVERROR_INVALIDDATA;
if ((ret = ff_alloc_extradata(st->codecpar, 16)) < 0)
return ret;