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lavf/mov.c: Use the correct offset to shift timestamp when seeking.

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Fixes seek for files with empty edits and files with negative ctts
(dts_shift > 0). Added fate samples and tests.

Signed-off-by: Sasi Inguva <isasi@isasi.mtv.corp.google.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Sasi Inguva 2018-03-09 13:30:21 -08:00 • committed by Michael Niedermayer
parent b6fc09cdb4
commit 43205df645
6 changed files with 401 additions and 11 deletions
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1
libavformat/isom.h
View file

@ -168,6 +168,7 @@ typedef struct MOVStreamContext {
int *keyframes;
int time_scale;
int64_t time_offset; ///< time offset of the edit list entries
int64_t min_corrected_pts; ///< minimum Composition time shown by the edits excluding empty edits.
int current_sample;
int64_t current_index;
MOVIndexRange* index_ranges;

27
libavformat/mov.c
View file

@ -3378,7 +3378,6 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
int64_t edit_list_start_ctts_sample = 0;
int64_t curr_cts;
int64_t curr_ctts = 0;
int64_t min_corrected_pts = -1;
int64_t empty_edits_sum_duration = 0;
int64_t edit_list_index = 0;
int64_t index;
@ -3419,6 +3418,9 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
msc->ctts_sample = 0;
msc->ctts_allocated_size = 0;
// Reinitialize min_corrected_pts so that it can be computed again.
msc->min_corrected_pts = -1;
// If the dts_shift is positive (in case of negative ctts values in mov),
// then negate the DTS by dts_shift
if (msc->dts_shift > 0) {
@ -3563,10 +3565,10 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
}
}
} else {
if (min_corrected_pts < 0) {
min_corrected_pts = edit_list_dts_counter + curr_ctts + msc->dts_shift;
if (msc->min_corrected_pts < 0) {
msc->min_corrected_pts = edit_list_dts_counter + curr_ctts + msc->dts_shift;
} else {
min_corrected_pts = FFMIN(min_corrected_pts, edit_list_dts_counter + curr_ctts + msc->dts_shift);
msc->min_corrected_pts = FFMIN(msc->min_corrected_pts, edit_list_dts_counter + curr_ctts + msc->dts_shift);
}
if (edit_list_start_encountered == 0) {
edit_list_start_encountered = 1;
@ -3625,16 +3627,16 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
}
}
}
// If there are empty edits, then min_corrected_pts might be positive intentionally. So we subtract the
// sum duration of emtpy edits here.
min_corrected_pts -= empty_edits_sum_duration;
// If there are empty edits, then msc->min_corrected_pts might be positive
// intentionally. So we subtract the sum duration of emtpy edits here.
msc->min_corrected_pts -= empty_edits_sum_duration;
// If the minimum pts turns out to be greater than zero after fixing the index, then we subtract the
// dts by that amount to make the first pts zero.
if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && min_corrected_pts > 0) {
av_log(mov->fc, AV_LOG_DEBUG, "Offset DTS by %"PRId64" to make first pts zero.\n", min_corrected_pts);
if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && msc->min_corrected_pts > 0) {
av_log(mov->fc, AV_LOG_DEBUG, "Offset DTS by %"PRId64" to make first pts zero.\n", msc->min_corrected_pts);
for (i = 0; i < st->nb_index_entries; ++i) {
st->index_entries[i].timestamp -= min_corrected_pts;
st->index_entries[i].timestamp -= msc->min_corrected_pts;
}
}
@ -3697,6 +3699,7 @@ static void mov_build_index(MOVContext *mov, AVStream *st)
if (empty_duration)
empty_duration = av_rescale(empty_duration, sc->time_scale, mov->time_scale);
sc->time_offset = start_time - empty_duration;
sc->min_corrected_pts = start_time;
if (!mov->advanced_editlist)
current_dts = -sc->time_offset;
}
@ -7158,7 +7161,9 @@ static int mov_seek_stream(AVFormatContext *s, AVStream *st, int64_t timestamp,
int sample, time_sample, ret;
unsigned int i;
timestamp -= sc->time_offset;
// Here we consider timestamp to be PTS, hence try to offset it so that we
// can search over the DTS timeline.
timestamp -= (sc->min_corrected_pts + sc->dts_shift);
ret = mov_seek_fragment(s, st, timestamp);
if (ret < 0)