From 9d599e3f6e61438772d8cddd6c9b7c495251f51e Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Wed, 2 Apr 2014 09:11:10 +0200 Subject: [PATCH] avi: Improve non-interleaved detection Additional fixes by Nigel Touati-Evans . Check the index for streams with a time drift of 2s or a buffer drift of 64MB. Bug-Id: 666 CC: libav-stable@libav.org Sample-Id: yet-another-broken-interleaved-avi.avi Signed-off-by: Vittorio Giovara Signed-off-by: Luca Barbato Signed-off-by: Diego Biurrun --- libavformat/avidec.c | 70 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 68 insertions(+), 2 deletions(-) diff --git a/libavformat/avidec.c b/libavformat/avidec.c index a2c230cd7c..c24a6c495d 100644 --- a/libavformat/avidec.c +++ b/libavformat/avidec.c @@ -795,7 +795,11 @@ fail: if (!avi->index_loaded && pb->seekable) avi_load_index(s); avi->index_loaded = 1; - avi->non_interleaved |= guess_ni_flag(s); + + if ((ret = guess_ni_flag(s)) < 0) + return ret; + + avi->non_interleaved |= ret; for (i = 0; i < s->nb_streams; i++) { AVStream *st = s->streams[i]; if (st->nb_index_entries) @@ -1307,6 +1311,64 @@ static int avi_read_idx1(AVFormatContext *s, int size) return 0; } +/* Scan the index and consider any file with streams more than + * 2 seconds or 64MB apart non-interleaved. */ +static int check_stream_max_drift(AVFormatContext *s) +{ + int64_t min_pos, pos; + int i; + int *idx = av_mallocz_array(s->nb_streams, sizeof(*idx)); + if (!idx) + return AVERROR(ENOMEM); + + for (min_pos = pos = 0; min_pos != INT64_MAX; pos = min_pos + 1LU) { + int64_t max_dts = INT64_MIN / 2; + int64_t min_dts = INT64_MAX / 2; + int64_t max_buffer = 0; + + min_pos = INT64_MAX; + + for (i = 0; i < s->nb_streams; i++) { + AVStream *st = s->streams[i]; + AVIStream *ast = st->priv_data; + int n = st->nb_index_entries; + while (idx[i] < n && st->index_entries[idx[i]].pos < pos) + idx[i]++; + if (idx[i] < n) { + int64_t dts; + dts = av_rescale_q(st->index_entries[idx[i]].timestamp / + FFMAX(ast->sample_size, 1), + st->time_base, AV_TIME_BASE_Q); + min_dts = FFMIN(min_dts, dts); + min_pos = FFMIN(min_pos, st->index_entries[idx[i]].pos); + } + } + for (i = 0; i < s->nb_streams; i++) { + AVStream *st = s->streams[i]; + AVIStream *ast = st->priv_data; + + if (idx[i] && min_dts != INT64_MAX / 2) { + int64_t dts; + dts = av_rescale_q(st->index_entries[idx[i] - 1].timestamp / + FFMAX(ast->sample_size, 1), + st->time_base, AV_TIME_BASE_Q); + max_dts = FFMAX(max_dts, dts); + max_buffer = FFMAX(max_buffer, + av_rescale(dts - min_dts, + st->codec->bit_rate, + AV_TIME_BASE)); + } + } + if (max_dts - min_dts > 2 * AV_TIME_BASE || + max_buffer > 1024 * 1024 * 8 * 8) { + av_free(idx); + return 1; + } + } + av_free(idx); + return 0; +} + static int guess_ni_flag(AVFormatContext *s) { int i; @@ -1336,7 +1398,11 @@ static int guess_ni_flag(AVFormatContext *s) first_end = st->index_entries[n - 1].pos; } avio_seek(s->pb, oldpos, SEEK_SET); - return last_start > first_end; + + if (last_start > first_end) + return 1; + + return check_stream_max_drift(s); } static int avi_load_index(AVFormatContext *s)