Hi,
On Mon, Jan 9, 2012 at 1:50 PM, Aneesh Dogra <[email protected]> wrote:
> +static int get_nb_samples(AVCodecContext *avctx, GetByteContext *g,
> + int *coded_samples)
> {
> ADPCMDecodeContext *s = avctx->priv_data;
Add GetByteContext to ADPCMDecodeContext, so we don't need extra
function arguments.
> int nb_samples = 0;
> int ch = avctx->channels;
> int has_coded_samples = 0;
> int header_size;
> + int buf_size = bytestream2_get_bytes_left(g);
Why do you need to know buf_size here? Ideally all these buf_size
checks can now disappear.
> - if (*src++) av_log(avctx, AV_LOG_ERROR, "unused byte should be
> null but is %d!!\n", src[-1]); /* unused */
> + if (bytestream2_peek_byte(&g))
> + av_log(avctx, AV_LOG_ERROR,
> + "unused byte should be null but is %d!!\n",
> + bytestream2_peek_byte(&g)); /* unused */
> + bytestream2_skip(&g, 1);
> }
unsigned int tmp = bytestream2_get_byte(&g);
if (tmp)
av_log(.., "Bla is not null: %d\n", tmp);
> - case CODEC_ID_ADPCM_XA:
> - while (buf_size >= 128) {
> - xa_decode(samples, src, &c->status[0], &c->status[1],
> + case CODEC_ID_ADPCM_XA: {
> + unsigned char buffer[128];
> + while (bytestream2_get_bytes_left(&g) >= 128) {
> + bytestream2_get_buffer(&g, buffer, 128);
> + xa_decode(samples, buffer, &c->status[0], &c->status[1],
> avctx->channels);
> - src += 128;
> samples += 28 * 8;
> buf_size -= 128;
> }
> break;
No. xa_decode() is now still vulnerable to overreads.
> for (count2=0; count2<28; count2++) {
> if (count2 & 1)
> - next_sample = sign_extend(*srcC++, 4) <<
> shift;
> + next_sample =
> sign_extend(bytestream2_get_byte(&g), 4) << shift;
> else
> - next_sample = sign_extend(*srcC >> 4, 4) <<
> shift;
> + next_sample =
> sign_extend(bytestream2_peek_byte(&g) >> 4, 4) << shift;
Unroll this:
for (count2 = 0; count2 < 14; count2++) {
unsigned int tmp = bytestream2_get_byte();
next_sample = .. & 0xf;
..
next_sample = .. >> 4;
..
}
Ronald
_______________________________________________
libav-devel mailing list
[email protected]
https://lists.libav.org/mailman/listinfo/libav-devel
