It works in three mode:
0: don't ignore in-band ps
1: ignore in-band ps
-1: if corrupted data is detected, then ignore in-band ps afterwards
h264dec working hard to do error resilience, it doesn't drop a
whole packet when error is detected in a nalu. Then there is a
higher chance for fake sps/pps be found and used. This happened
in a mp4 file. h264dec failed to recovery after broken data due
to the fake pps, while other H.264 decoders have no such problem.
---
libavcodec/h264dec.c | 17 ++++++++++++++++-
libavcodec/h264dec.h | 1 +
2 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/libavcodec/h264dec.c b/libavcodec/h264dec.c
index a47caa95e8..1ee2b68459 100644
--- a/libavcodec/h264dec.c
+++ b/libavcodec/h264dec.c
@@ -681,6 +681,10 @@ static int decode_nal_units(H264Context *h, const uint8_t
*buf, int buf_size)
break;
case H264_NAL_SPS: {
GetBitContext tmp_gb = nal->gb;
+ if (h->ps.sps && h->ignore_in_band_ps == 1) {
+ av_log(h, AV_LOG_WARNING, "ignore in-band sps\n");
+ break;
+ }
if (avctx->hwaccel && avctx->hwaccel->decode_params) {
ret = avctx->hwaccel->decode_params(avctx,
nal->type,
@@ -700,6 +704,10 @@ static int decode_nal_units(H264Context *h, const uint8_t
*buf, int buf_size)
break;
}
case H264_NAL_PPS:
+ if (h->ps.pps && h->ignore_in_band_ps == 1) {
+ av_log(h, AV_LOG_WARNING, "ignore in-band pps\n");
+ break;
+ }
if (avctx->hwaccel && avctx->hwaccel->decode_params) {
ret = avctx->hwaccel->decode_params(avctx,
nal->type,
@@ -726,6 +734,8 @@ static int decode_nal_units(H264Context *h, const uint8_t
*buf, int buf_size)
}
if (err < 0) {
+ if (h->ignore_in_band_ps == -1)
+ h->ignore_in_band_ps = 1;
av_log(h->avctx, AV_LOG_ERROR, "decode_slice_header error\n");
}
}
@@ -1011,8 +1021,12 @@ static int h264_decode_frame(AVCodecContext *avctx, void
*data,
}
buf_index = decode_nal_units(h, buf, buf_size);
- if (buf_index < 0)
+ if (buf_index < 0) {
+ /* If there is corrupted data, then don't trust the in-band ps. */
+ if (h->ignore_in_band_ps == -1)
+ h->ignore_in_band_ps = 1;
return AVERROR_INVALIDDATA;
+ }
if (!h->cur_pic_ptr && h->nal_unit_type == H264_NAL_END_SEQUENCE) {
av_assert0(buf_index <= buf_size);
@@ -1055,6 +1069,7 @@ static const AVOption h264_options[] = {
{ "nal_length_size", "nal_length_size", OFFSET(nal_length_size),
AV_OPT_TYPE_INT, {.i64 = 0}, 0, 4, VDX },
{ "enable_er", "Enable error resilience on damaged frames (unsafe)",
OFFSET(enable_er), AV_OPT_TYPE_BOOL, { .i64 = -1 }, -1, 1, VD },
{ "x264_build", "Assume this x264 version if no x264 version found in any
SEI", OFFSET(x264_build), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, VD },
+ { "ignore_in_band_ps", "ignore in-band parameter set",
OFFSET(ignore_in_band_ps), AV_OPT_TYPE_INT, {.i64 = 0}, -1, 1, VD },
{ NULL },
};
diff --git a/libavcodec/h264dec.h b/libavcodec/h264dec.h
index 8168c8e97b..760540bc9d 100644
--- a/libavcodec/h264dec.h
+++ b/libavcodec/h264dec.h
@@ -448,6 +448,7 @@ typedef struct H264Context {
int bit_depth_luma; ///< luma bit depth from sps to detect changes
int chroma_format_idc; ///< chroma format from sps to detect changes
+ int ignore_in_band_ps;
H264ParamSets ps;
uint16_t *slice_table_base;
--
2.31.1
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