libavformat/vvc: Make probe more conservative

Reduce false positives for VVC files by adding additional checks in
`vvc_probe`. Specifically, `nuh_temporal_id_plus1` is tested for valid
values in extra cases depending on the NAL unit type, as per ITU-T H.266
section 7.4.2.2.

Resolves trac #10703.

Signed-off-by: Frank Plowman <post@frankplowman.com>
Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>
(cherry picked from commit 7d7ba2175c)
pull/390/head
Frank Plowman 1 year ago committed by Zhao Zhili
parent 884a660cae
commit a888d21c8c
  1. 18
      libavformat/vvcdec.c

@ -24,6 +24,22 @@
#include "avformat.h"
#include "rawdec.h"
static int check_temporal_id(uint8_t nuh_temporal_id_plus1, int type)
{
if (nuh_temporal_id_plus1 == 0)
return 0;
if (nuh_temporal_id_plus1 != 1) {
if (type >= VVC_IDR_W_RADL && type <= VVC_RSV_IRAP_11
|| type == VVC_DCI_NUT || type == VVC_OPI_NUT
|| type == VVC_VPS_NUT || type == VVC_SPS_NUT
|| type == VVC_EOS_NUT || type == VVC_EOB_NUT)
return 0;
}
return 1;
}
static int vvc_probe(const AVProbeData *p)
{
uint32_t code = -1;
@ -39,7 +55,7 @@ static int vvc_probe(const AVProbeData *p)
if (code & 0x80) // forbidden_zero_bit
return 0;
if ((nal2 & 0x7) == 0) // nuh_temporal_id_plus1
if (!check_temporal_id(nal2 & 0x7, type))
return 0;
switch (type) {

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