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ttadec: CRC checking

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Signed-off-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Justin Ruggles <justin.ruggles@gmail.com>
This commit is contained in:
Paul B Mahol 2012-02-11 21:30:30 +00:00 committed by Justin Ruggles
parent 4ace130ee6
commit 2af3dc8698
1 changed files with 33 additions and 0 deletions
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33
libavcodec/tta.c
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@ -32,6 +32,7 @@
#include <limits.h>
#include "avcodec.h"
#include "get_bits.h"
#include "libavutil/crc.h"
#define FORMAT_SIMPLE 1
#define FORMAT_ENCRYPTED 2
@ -58,6 +59,7 @@ typedef struct TTAContext {
AVCodecContext *avctx;
AVFrame frame;
GetBitContext gb;
const AVCRC *crc_table;
int format, channels, bps, data_length;
int frame_length, last_frame_length, total_frames;
@ -188,6 +190,20 @@ static int tta_get_unary(GetBitContext *gb)
return ret;
}
static int tta_check_crc(TTAContext *s, const uint8_t *buf, int buf_size)
{
uint32_t crc, CRC;
CRC = AV_RL32(buf + buf_size);
crc = av_crc(s->crc_table, 0xFFFFFFFFU, buf, buf_size);
if (CRC != (crc ^ 0xFFFFFFFFU)) {
av_log(s->avctx, AV_LOG_ERROR, "CRC error\n");
return AVERROR_INVALIDDATA;
}
return 0;
}
static av_cold int tta_decode_init(AVCodecContext * avctx)
{
TTAContext *s = avctx->priv_data;
@ -201,6 +217,12 @@ static av_cold int tta_decode_init(AVCodecContext * avctx)
init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size * 8);
if (show_bits_long(&s->gb, 32) == AV_RL32("TTA1"))
{
if (avctx->err_recognition & AV_EF_CRCCHECK) {
s->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);
if (tta_check_crc(s, avctx->extradata, 18))
return AVERROR_INVALIDDATA;
}
/* signature */
skip_bits_long(&s->gb, 32);
@ -260,6 +282,12 @@ static av_cold int tta_decode_init(AVCodecContext * avctx)
s->data_length, s->frame_length, s->last_frame_length, s->total_frames);
// FIXME: seek table
if (get_bits_left(&s->gb) < 32 * s->total_frames + 32)
av_log(avctx, AV_LOG_WARNING, "Seek table missing or too small\n");
else if (avctx->err_recognition & AV_EF_CRCCHECK) {
if (tta_check_crc(s, avctx->extradata + 22, s->total_frames * 4))
return AVERROR_INVALIDDATA;
}
skip_bits_long(&s->gb, 32 * s->total_frames);
skip_bits_long(&s->gb, 32); // CRC32 of seektable
@ -299,6 +327,11 @@ static int tta_decode_frame(AVCodecContext *avctx, void *data,
int cur_chan = 0, framelen = s->frame_length;
int32_t *p;
if (avctx->err_recognition & AV_EF_CRCCHECK) {
if (buf_size < 4 || tta_check_crc(s, buf, buf_size - 4))
return AVERROR_INVALIDDATA;
}
init_get_bits(&s->gb, buf, buf_size*8);
// FIXME: seeking