From 3aa661ec561d7a20812b84b353b0d7855ac346c8 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 1 Oct 2011 17:41:28 +0200 Subject: [PATCH] h264: improve parsing of broken AVC SPS Parsing the entire NAL as SPS fixes decoding of some AVC bitstreams with broken escaping. Since the size of the NAL unit is known and checked against the buffer end we can parse it entirely without buffer overreads. Fixes playback of http://streams.videolan.org/streams/mp4/Mr_MrsSmith-h264_aac.mp4 Signed-off-by: Janne Grunau --- libavcodec/h264.c | 9 ++++++++- libavcodec/h264_ps.c | 5 ++++- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/libavcodec/h264.c b/libavcodec/h264.c index 20aed27fd1..c3ef3f0110 100644 --- a/libavcodec/h264.c +++ b/libavcodec/h264.c @@ -3925,7 +3925,14 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size){ break; case NAL_SPS: init_get_bits(&s->gb, ptr, bit_length); - ff_h264_decode_seq_parameter_set(h); + if (ff_h264_decode_seq_parameter_set(h) < 0 && + h->is_avc && (nalsize != consumed) && nalsize) { + av_log(h->s.avctx, AV_LOG_DEBUG, "SPS decoding failure, " + "try parsing the coomplete NAL\n"); + init_get_bits(&s->gb, buf + buf_index + 1 - consumed, + 8 * (nalsize - 1)); + ff_h264_decode_seq_parameter_set(h); + } if (s->flags& CODEC_FLAG_LOW_DELAY || (h->sps.bitstream_restriction_flag && !h->sps.num_reorder_frames)) diff --git a/libavcodec/h264_ps.c b/libavcodec/h264_ps.c index 287702c7c4..276eb77d1d 100644 --- a/libavcodec/h264_ps.c +++ b/libavcodec/h264_ps.c @@ -228,7 +228,6 @@ static inline int decode_vui_parameters(H264Context *h, SPS *sps){ get_ue_golomb(&s->gb); /*max_dec_frame_buffering*/ if (get_bits_left(&s->gb) < 0) { - av_log(h->s.avctx, AV_LOG_ERROR, "Overread VUI by %d bits\n", -get_bits_left(&s->gb)); sps->num_reorder_frames=0; sps->bitstream_restriction_flag= 0; } @@ -238,6 +237,10 @@ static inline int decode_vui_parameters(H264Context *h, SPS *sps){ return -1; } } + if (get_bits_left(&s->gb) < 0) { + av_log(h->s.avctx, AV_LOG_ERROR, "Overread VUI by %d bits\n", -get_bits_left(&s->gb)); + return AVERROR_INVALIDDATA; + } return 0; }