From 5fa739e685bcbd29dd83139c245935099112beed Mon Sep 17 00:00:00 2001 From: Janne Grunau Date: Fri, 16 Nov 2012 14:31:09 +0100 Subject: [PATCH] h264: enable low delay only if no delayed frames were seen Dropping frames is undesirable but that is the only way by which the decoder could return to low delay mode. Instead emit a warning and continue with delayed frames. Fixes a crash in fuzzed sample nasa-8s2.ts_s20033 caused by a larger than expected has_b_frames value. Low delay keeps getting re-enabled from a presumely broken SPS. CC: libav-stable@libav.org (cherry picked from commit 706acb558a38eba633056773280155d66c2f4b24) Conflicts: libavcodec/h264.c --- libavcodec/h264.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/libavcodec/h264.c b/libavcodec/h264.c index 0940335edf..98c68d873f 100644 --- a/libavcodec/h264.c +++ b/libavcodec/h264.c @@ -3847,9 +3847,16 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size){ init_get_bits(&s->gb, ptr, bit_length); ff_h264_decode_seq_parameter_set(h); - if (s->flags& CODEC_FLAG_LOW_DELAY || - (h->sps.bitstream_restriction_flag && !h->sps.num_reorder_frames)) - s->low_delay=1; + if (s->flags & CODEC_FLAG_LOW_DELAY || + (h->sps.bitstream_restriction_flag && + !h->sps.num_reorder_frames)) { + if (s->avctx->has_b_frames > 1 || h->delayed_pic[0]) + av_log(avctx, AV_LOG_WARNING, "Delayed frames seen " + "reenabling low delay requires a codec " + "flush.\n"); + else + s->low_delay = 1; + } if(avctx->has_b_frames < 2) avctx->has_b_frames= !s->low_delay;