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Code Issues Releases Activity

mpc7: simplify handling of packet sizes that are not a multiple of 4 bytes

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This commit is contained in:
Justin Ruggles 2012-02-01 15:19:50 -05:00
parent 41dd77bdbc
commit b5b825c381
1 changed files with 26 additions and 14 deletions
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40
libavcodec/mpc7.c
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@ -200,35 +200,47 @@ static int mpc7_decode_frame(AVCodecContext * avctx, void *data,
int *got_frame_ptr, AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
int buf_size;
MPCContext *c = avctx->priv_data;
GetBitContext gb;
uint8_t *bits;
int i, ch;
int mb = -1;
Band *bands = c->bands;
int off, ret;
int off, ret, last_frame, skip;
int bits_used, bits_avail;
memset(bands, 0, sizeof(*bands) * (c->maxbands + 1));
if(buf_size <= 4){
av_log(avctx, AV_LOG_ERROR, "Too small buffer passed (%i bytes)\n", buf_size);
return AVERROR(EINVAL);
buf_size = avpkt->size & ~3;
if (buf_size <= 0) {
av_log(avctx, AV_LOG_ERROR, "packet size is too small (%i bytes)\n",
avpkt->size);
return AVERROR_INVALIDDATA;
}
if (buf_size != avpkt->size) {
av_log(avctx, AV_LOG_WARNING, "packet size is not a multiple of 4. "
"extra bytes at the end will be skipped.\n");
}
skip = buf[0];
last_frame = buf[1];
buf += 4;
buf_size -= 4;
/* get output buffer */
c->frame.nb_samples = buf[1] ? c->lastframelen : MPC_FRAME_SIZE;
c->frame.nb_samples = last_frame ? c->lastframelen : MPC_FRAME_SIZE;
if ((ret = avctx->get_buffer(avctx, &c->frame)) < 0) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return ret;
}
bits = av_malloc(((buf_size - 1) & ~3) + FF_INPUT_BUFFER_PADDING_SIZE);
bits = av_malloc(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
if (!bits)
return AVERROR(ENOMEM);
c->dsp.bswap_buf((uint32_t*)bits, (const uint32_t*)(buf + 4), (buf_size - 4) >> 2);
init_get_bits(&gb, bits, (buf_size - 4)* 8);
skip_bits_long(&gb, buf[0]);
c->dsp.bswap_buf((uint32_t *)bits, (const uint32_t *)buf, buf_size >> 2);
init_get_bits(&gb, bits, buf_size * 8);
skip_bits_long(&gb, skip);
/* read subband indexes */
for(i = 0; i <= c->maxbands; i++){
@ -287,21 +299,21 @@ static int mpc7_decode_frame(AVCodecContext * avctx, void *data,
av_free(bits);
bits_used = get_bits_count(&gb);
bits_avail = (buf_size - 4) * 8;
if(!buf[1] && ((bits_avail < bits_used) || (bits_used + 32 <= bits_avail))){
bits_avail = buf_size * 8;
if (!last_frame && ((bits_avail < bits_used) || (bits_used + 32 <= bits_avail))) {
av_log(NULL,0, "Error decoding frame: used %i of %i bits\n", bits_used, bits_avail);
return -1;
}
if(c->frames_to_skip){
c->frames_to_skip--;
*got_frame_ptr = 0;
return buf_size;
return avpkt->size;
}
*got_frame_ptr = 1;
*(AVFrame *)data = c->frame;
return buf_size;
return avpkt->size;
}
static void mpc7_decode_flush(AVCodecContext *avctx)