Fixes t/6421. If the videos starts with B frame, then the minimum composition
time as computed by stts + ctts will be non-zero. Hence we need to shift the
DTS, so that the first pts is zero. This was the intention of that code-block.
However it was subtracting by the wrong amount.
For example, for one of the videos in the bug nonFormatted.mp4 we have
stts:
sample_count duration
960 1001
ctts:
sample_count duration
1 3003
2 0
1 3003
....
The resulting composition times are : 3003, 1001, 2002, 6006, ...
The minimum composition time or PTS is 1001, which should be used to offset
DTS. However the code block was wrongly using ctts[0] which is 3003. Hence the
PTS was negative. This change computes the minimum pts encountered while fixing
the index, and then subtracts it from all the timestamps after the edit list
fixes are applied.
fate-suite/h264/twofields_packet.mp4 is a similar file starting with 2 Bframes.
Before this change the PTS of first two B-frames was -6006 and -3003, and I am
guessing one of them got dropped when being decoded and remuxed to the
framecrc before, and now it is not being dropped.
Signed-off-by: Sasi Inguva <is...@google.com>
---
libavformat/mov.c | 57 ++++++++++++++++++++++++----------
tests/ref/fate/h264-twofields-packet | 60 ++++++++++++++++++------------------
2 files changed, 70 insertions(+), 47 deletions(-)
diff --git a/libavformat/mov.c b/libavformat/mov.c
index 3845e63b53..d7d64c3361 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -3039,6 +3039,9 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
int64_t edit_list_dts_entry_end = 0;
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;
int64_t index_ctts_count;
@@ -3053,6 +3056,7 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
int first_non_zero_audio_edit = -1;
int packet_skip_samples = 0;
MOVIndexRange *current_index_range;
+ int i;
if (!msc->elst_data || msc->elst_count <= 0 || nb_old <= 0) {
return;
@@ -3080,13 +3084,9 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
// 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)
+ if (msc->dts_shift > 0) {
edit_list_dts_entry_end -= msc->dts_shift;
-
- // Offset the DTS by ctts[0] to make the PTS of the first frame 0
- if (ctts_data_old && ctts_count_old > 0) {
- edit_list_dts_entry_end -= ctts_data_old[0].duration;
- av_log(mov->fc, AV_LOG_DEBUG, "Offset DTS by ctts[%d].duration: %d\n",
0, ctts_data_old[0].duration);
+ av_log(mov->fc, AV_LOG_DEBUG, "Shifting DTS by %d because of negative
CTTS.\n", msc->dts_shift);
}
start_dts = edit_list_dts_entry_end;
@@ -3100,6 +3100,7 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
edit_list_dts_entry_end += edit_list_duration;
num_discarded_begin = 0;
if (edit_list_media_time == -1) {
+ empty_edits_sum_duration += edit_list_duration;
continue;
}
@@ -3179,11 +3180,13 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
// frames (pts) before or after edit list
curr_cts = current->timestamp + msc->dts_shift;
+ curr_ctts = 0;
if (ctts_data_old && ctts_index_old < ctts_count_old) {
- av_log(mov->fc, AV_LOG_DEBUG, "shifted frame pts, curr_cts:
%"PRId64" @ %"PRId64", ctts: %d, ctts_count: %"PRId64"\n",
- curr_cts, ctts_index_old,
ctts_data_old[ctts_index_old].duration, ctts_count_old);
- curr_cts += ctts_data_old[ctts_index_old].duration;
+ curr_ctts = ctts_data_old[ctts_index_old].duration;
+ av_log(mov->fc, AV_LOG_DEBUG, "stts: %"PRId64" ctts:
%"PRId64", ctts_index: %"PRId64", ctts_count: %"PRId64"\n",
+ curr_cts, curr_ctts, ctts_index_old, ctts_count_old);
+ curr_cts += curr_ctts;
ctts_sample_old++;
if (ctts_sample_old == ctts_data_old[ctts_index_old].count) {
if (add_ctts_entry(&msc->ctts_data, &msc->ctts_count,
@@ -3244,14 +3247,21 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
}
}
}
- } else if (edit_list_start_encountered == 0) {
- edit_list_start_encountered = 1;
- // Make timestamps strictly monotonically increasing for
audio, by rewriting timestamps for
- // discarded packets.
- if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO &&
frame_duration_buffer) {
- fix_index_entry_timestamps(st, st->nb_index_entries,
edit_list_dts_counter,
- frame_duration_buffer,
num_discarded_begin);
- av_freep(&frame_duration_buffer);
+ } else {
+ if (min_corrected_pts < 0) {
+ 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);
+ }
+ if (edit_list_start_encountered == 0) {
+ edit_list_start_encountered = 1;
+ // Make timestamps strictly monotonically increasing for
audio, by rewriting timestamps for
+ // discarded packets.
+ if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO &&
frame_duration_buffer) {
+ fix_index_entry_timestamps(st, st->nb_index_entries,
edit_list_dts_counter,
+ frame_duration_buffer,
num_discarded_begin);
+ av_freep(&frame_duration_buffer);
+ }
}
}
@@ -3292,6 +3302,19 @@ 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 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);
+ for (i = 0; i < st->nb_index_entries; ++i) {
+ st->index_entries[i].timestamp -= min_corrected_pts;
+ }
+ }
+
// Update av stream length
st->duration = edit_list_dts_entry_end - start_dts;
diff --git a/tests/ref/fate/h264-twofields-packet
b/tests/ref/fate/h264-twofields-packet
index 4cff0a15bd..db12498f15 100644
--- a/tests/ref/fate/h264-twofields-packet
+++ b/tests/ref/fate/h264-twofields-packet
@@ -3,33 +3,33 @@
#codec_id 0: rawvideo
#dimensions 0: 1920x1080
#sar 0: 1/1
-0, 0, 0, 1, 3110400, 0x40d65f69
-0, 1, 1, 1, 3110400, 0xdcbc50bf
-0, 2, 2, 1, 3110400, 0x73a2276a
-0, 3, 3, 1, 3110400, 0x84a2b3c6
-0, 4, 4, 1, 3110400, 0x7cf3b570
-0, 5, 5, 1, 3110400, 0xa2d1e03a
-0, 6, 6, 1, 3110400, 0x03220fb1
-0, 7, 7, 1, 3110400, 0x89cd526a
-0, 8, 8, 1, 3110400, 0xbb4b7531
-0, 9, 9, 1, 3110400, 0x0a69f053
-0, 10, 10, 1, 3110400, 0x0187994b
-0, 11, 11, 1, 3110400, 0x26ed49fa
-0, 12, 12, 1, 3110400, 0xbe8966d4
-0, 13, 13, 1, 3110400, 0x248d203c
-0, 14, 14, 1, 3110400, 0x3139c754
-0, 15, 15, 1, 3110400, 0xf22380c4
-0, 16, 16, 1, 3110400, 0x3e00dcc1
-0, 17, 17, 1, 3110400, 0x8cbe2483
-0, 18, 18, 1, 3110400, 0x6951cd63
-0, 19, 19, 1, 3110400, 0x36aca4c5
-0, 20, 20, 1, 3110400, 0x4d4f6fbe
-0, 21, 21, 1, 3110400, 0x997247aa
-0, 22, 22, 1, 3110400, 0x0fd40e06
-0, 23, 23, 1, 3110400, 0xa10d2d67
-0, 24, 24, 1, 3110400, 0x87c481da
-0, 25, 25, 1, 3110400, 0xe3dca3cd
-0, 26, 26, 1, 3110400, 0x5f77b078
-0, 27, 27, 1, 3110400, 0xf1ddd098
-0, 28, 28, 1, 3110400, 0xedcd1754
-0, 29, 29, 1, 3110400, 0x14ac7153
+0, 0, 0, 1, 3110400, 0x48e39acd
+0, 1, 1, 1, 3110400, 0x40d65f69
+0, 2, 2, 1, 3110400, 0xdcbc50bf
+0, 3, 3, 1, 3110400, 0x73a2276a
+0, 4, 4, 1, 3110400, 0x84a2b3c6
+0, 5, 5, 1, 3110400, 0x7cf3b570
+0, 6, 6, 1, 3110400, 0xa2d1e03a
+0, 7, 7, 1, 3110400, 0x03220fb1
+0, 8, 8, 1, 3110400, 0x89cd526a
+0, 9, 9, 1, 3110400, 0xbb4b7531
+0, 10, 10, 1, 3110400, 0x0a69f053
+0, 11, 11, 1, 3110400, 0x0187994b
+0, 12, 12, 1, 3110400, 0x26ed49fa
+0, 13, 13, 1, 3110400, 0xbe8966d4
+0, 14, 14, 1, 3110400, 0x248d203c
+0, 15, 15, 1, 3110400, 0x3139c754
+0, 16, 16, 1, 3110400, 0xf22380c4
+0, 17, 17, 1, 3110400, 0x3e00dcc1
+0, 18, 18, 1, 3110400, 0x8cbe2483
+0, 19, 19, 1, 3110400, 0x6951cd63
+0, 20, 20, 1, 3110400, 0x36aca4c5
+0, 21, 21, 1, 3110400, 0x4d4f6fbe
+0, 22, 22, 1, 3110400, 0x997247aa
+0, 23, 23, 1, 3110400, 0x0fd40e06
+0, 24, 24, 1, 3110400, 0xa10d2d67
+0, 25, 25, 1, 3110400, 0x87c481da
+0, 26, 26, 1, 3110400, 0xe3dca3cd
+0, 27, 27, 1, 3110400, 0x5f77b078
+0, 28, 28, 1, 3110400, 0xf1ddd098
+0, 29, 29, 1, 3110400, 0xedcd1754
--
2.13.0.506.g27d5fe0cd-goog
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