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lavf/mov.c: Refine edit list start seek, based on PTS computed from CTTS.

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Partially fixes t/6699.

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Sasi Inguva 2017-11-02 17:33:28 -07:00 committed by Michael Niedermayer
parent 9d0b42bce5
commit c2a8f0fcbe
3 changed files with 127 additions and 43 deletions
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129
libavformat/mov.c
View File

@ -3014,34 +3014,99 @@ static int get_edit_list_entry(MOVContext *mov,
}
/**
* Find the closest previous frame to the timestamp, in e_old index
* Find the closest previous frame to the timestamp_pts, in e_old index
* entries. Searching for just any frame / just key frames can be controlled by
* last argument 'flag'.
* Returns the index of the entry in st->index_entries if successful,
* else returns -1.
* Note that if ctts_data is not NULL, we will always search for a key frame
* irrespective of the value of 'flag'. If we don't find any keyframe, we will
* return the first frame of the video.
*
* Here the timestamp_pts is considered to be a presentation timestamp and
* the timestamp of index entries are considered to be decoding timestamps.
*
* Returns 0 if successful in finding a frame, else returns -1.
* Places the found index corresponding output arg.
*
* If ctts_old is not NULL, then refines the searched entry by searching
* backwards from the found timestamp, to find the frame with correct PTS.
*
* Places the found ctts_index and ctts_sample in corresponding output args.
*/
static int64_t find_prev_closest_index(AVStream *st,
AVIndexEntry *e_old,
int nb_old,
int64_t timestamp,
int flag)
static int find_prev_closest_index(AVStream *st,
AVIndexEntry *e_old,
int nb_old,
MOVStts* ctts_data,
int64_t ctts_count,
int64_t timestamp_pts,
int flag,
int64_t* index,
int64_t* ctts_index,
int64_t* ctts_sample)
{
MOVStreamContext *msc = st->priv_data;
AVIndexEntry *e_keep = st->index_entries;
int nb_keep = st->nb_index_entries;
int64_t found = -1;
int64_t i = 0;
int64_t index_ctts_count;
av_assert0(index);
// If dts_shift > 0, then all the index timestamps will have to be offset by
// at least dts_shift amount to obtain PTS.
// Hence we decrement the searched timestamp_pts by dts_shift to find the closest index element.
if (msc->dts_shift > 0) {
timestamp_pts -= msc->dts_shift;
}
st->index_entries = e_old;
st->nb_index_entries = nb_old;
found = av_index_search_timestamp(st, timestamp, flag | AVSEEK_FLAG_BACKWARD);
*index = av_index_search_timestamp(st, timestamp_pts, flag | AVSEEK_FLAG_BACKWARD);
// Keep going backwards in the index entries until the timestamp is the same.
if (found >= 0) {
for (i = found; i > 0 && e_old[i].timestamp == e_old[i - 1].timestamp;
if (*index >= 0) {
for (i = *index; i > 0 && e_old[i].timestamp == e_old[i - 1].timestamp;
i--) {
if ((flag & AVSEEK_FLAG_ANY) ||
(e_old[i - 1].flags & AVINDEX_KEYFRAME)) {
found = i - 1;
*index = i - 1;
}
}
}
// If we have CTTS then refine the search, by searching backwards over PTS
// computed by adding corresponding CTTS durations to index timestamps.
if (ctts_data && *index >= 0) {
av_assert0(ctts_index);
av_assert0(ctts_sample);
// Find out the ctts_index for the found frame.
*ctts_index = 0;
*ctts_sample = 0;
for (index_ctts_count = 0; index_ctts_count < *index; index_ctts_count++) {
if (*ctts_index < ctts_count) {
(*ctts_sample)++;
if (ctts_data[*ctts_index].count == *ctts_sample) {
(*ctts_index)++;
*ctts_sample = 0;
}
}
}
while (*index >= 0 && (*ctts_index) >= 0) {
// Find a "key frame" with PTS <= timestamp_pts (So that we can decode B-frames correctly).
// No need to add dts_shift to the timestamp here becase timestamp_pts has already been
// compensated by dts_shift above.
if ((e_old[*index].timestamp + ctts_data[*ctts_index].duration) <= timestamp_pts &&
(e_old[*index].flags & AVINDEX_KEYFRAME)) {
break;
}
(*index)--;
if (*ctts_sample == 0) {
(*ctts_index)--;
if (*ctts_index >= 0)
*ctts_sample = ctts_data[*ctts_index].count - 1;
} else {
(*ctts_sample)--;
}
}
}
@ -3049,7 +3114,7 @@ static int64_t find_prev_closest_index(AVStream *st,
/* restore AVStream state*/
st->index_entries = e_keep;
st->nb_index_entries = nb_keep;
return found;
return *index >= 0 ? 0 : -1;
}
/**
@ -3220,10 +3285,8 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
int64_t empty_edits_sum_duration = 0;
int64_t edit_list_index = 0;
int64_t index;
int64_t index_ctts_count;
int flags;
int64_t start_dts = 0;
int64_t edit_list_media_time_dts = 0;
int64_t edit_list_start_encountered = 0;
int64_t search_timestamp = 0;
int64_t* frame_duration_buffer = NULL;
@ -3293,17 +3356,11 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
st->skip_samples = msc->start_pad = 0;
}
//find closest previous key frame
edit_list_media_time_dts = edit_list_media_time;
if (msc->dts_shift > 0) {
edit_list_media_time_dts -= msc->dts_shift;
}
// While reordering frame index according to edit list we must handle properly
// the scenario when edit list entry starts from none key frame.
// We find closest previous key frame and preserve it and consequent frames in index.
// All frames which are outside edit list entry time boundaries will be dropped after decoding.
search_timestamp = edit_list_media_time_dts;
search_timestamp = edit_list_media_time;
if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
// Audio decoders like AAC need need a decoder delay samples previous to the current sample,
// to correctly decode this frame. Hence for audio we seek to a frame 1 sec. before the
@ -3311,38 +3368,24 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
search_timestamp = FFMAX(search_timestamp - msc->time_scale, e_old[0].timestamp);
}
index = find_prev_closest_index(st, e_old, nb_old, search_timestamp, 0);
if (index == -1) {
if (find_prev_closest_index(st, e_old, nb_old, ctts_data_old, ctts_count_old, search_timestamp, 0,
&index, &ctts_index_old, &ctts_sample_old) < 0) {
av_log(mov->fc, AV_LOG_WARNING,
"st: %d edit list: %"PRId64" Missing key frame while searching for timestamp: %"PRId64"\n",
st->index, edit_list_index, search_timestamp);
index = find_prev_closest_index(st, e_old, nb_old, search_timestamp, AVSEEK_FLAG_ANY);
if (index == -1) {
if (find_prev_closest_index(st, e_old, nb_old, ctts_data_old, ctts_count_old, search_timestamp, AVSEEK_FLAG_ANY,
&index, &ctts_index_old, &ctts_sample_old) < 0) {
av_log(mov->fc, AV_LOG_WARNING,
"st: %d edit list %"PRId64" Cannot find an index entry before timestamp: %"PRId64".\n"
"Rounding edit list media time to zero.\n",
st->index, edit_list_index, search_timestamp);
index = 0;
ctts_index_old = 0;
ctts_sample_old = 0;
edit_list_media_time = 0;
}
}
current = e_old + index;
ctts_index_old = 0;
ctts_sample_old = 0;
// set ctts_index properly for the found key frame
for (index_ctts_count = 0; index_ctts_count < index; index_ctts_count++) {
if (ctts_data_old && ctts_index_old < ctts_count_old) {
ctts_sample_old++;
if (ctts_data_old[ctts_index_old].count == ctts_sample_old) {
ctts_index_old++;
ctts_sample_old = 0;
}
}
}
edit_list_start_ctts_sample = ctts_sample_old;
// Iterate over index and arrange it according to edit list

8
tests/fate/mov.mak
View File

@ -9,6 +9,7 @@ FATE_MOV = fate-mov-3elist \
fate-mov-invalid-elst-entry-count \
fate-mov-gpmf-remux \
fate-mov-440hz-10ms \
fate-mov-ibi-elst-starts-b \
FATE_MOV_FFPROBE = fate-mov-aac-2048-priming \
fate-mov-zombie \
@ -47,6 +48,13 @@ fate-mov-440hz-10ms: CMD = framemd5 -i $(TARGET_SAMPLES)/mov/440hz-10ms.m4a
# Makes sure that we handle invalid edit list entry count correctly.
fate-mov-invalid-elst-entry-count: CMD = framemd5 -flags +bitexact -i $(TARGET_SAMPLES)/mov/invalid_elst_entry_count.mov
# Makes sure that 1st key-frame is picked when,
# i) One B-frame between 2 key-frames
# ii) Edit list starts on B-frame.
# iii) Both key-frames have their DTS < edit list start
# i.e. Pts Order: I-B-I
fate-mov-ibi-elst-starts-b: CMD = framemd5 -flags +bitexact -i $(TARGET_SAMPLES)/mov/mov_ibi_elst_starts_b.mov
fate-mov-aac-2048-priming: CMD = run ffprobe$(PROGSSUF)$(EXESUF) -show_packets -print_format compact $(TARGET_SAMPLES)/mov/aac-2048-priming.mov
fate-mov-zombie: CMD = run ffprobe$(PROGSSUF)$(EXESUF) -show_streams -show_packets -show_frames -bitexact -print_format compact $(TARGET_SAMPLES)/mov/white_zombie_scrunch-part.mov

33
tests/ref/fate/mov-ibi-elst-starts-b Normal file
View File

@ -0,0 +1,33 @@
#format: frame checksums
#version: 2
#hash: MD5
#tb 0: 1/25
#media_type 0: video
#codec_id 0: rawvideo
#dimensions 0: 320x240
#sar 0: 1/1
#stream#, dts, pts, duration, size, hash
0, 0, 0, 1, 115200, 7e20f8729b6b53dc11791927bf4a5aec
0, 1, 1, 1, 115200, 4e5dc2b806e394cd666c968f736fecd0
0, 2, 2, 1, 115200, 7a3c7473d44c5f60c07655f6fc0c2ac3
0, 3, 3, 1, 115200, 038254422a603a3270c09cdcd149707b
0, 4, 4, 1, 115200, 7553b6b4547cb23ef8f0392ed5a5d4b0
0, 5, 5, 1, 115200, 6d017ede7f446124af7308667cb0dc41
0, 6, 6, 1, 115200, 77752f0288ae64f857732b8e62e47457
0, 7, 7, 1, 115200, d656833951af99330625f7c6de7685c4
0, 8, 8, 1, 115200, 14338b833e431e566ac98da841600bfe
0, 9, 9, 1, 115200, 07ea95d1659f3c4424a470a546d0df6e
0, 10, 10, 1, 115200, fd05b8cc83072f813e89d394d1f6efc6
0, 11, 11, 1, 115200, 750b82ca5c7e901545e7b1aa69692426
0, 12, 12, 1, 115200, 7347679ab09bc936047368b8caebcaff
0, 13, 13, 1, 115200, 63a23fdd57ac8462b9ffbcb12ab717b3
0, 14, 14, 1, 115200, 705257a1c99693db233e2a3ee027adcf
0, 15, 15, 1, 115200, df861a2ec7a4ef70e82b1c28025e5a48
0, 16, 16, 1, 115200, 2a8b403c077b6b43aa71eaf7d1537713
0, 17, 17, 1, 115200, 973b5cd3ce473e3970dfa96045553172
0, 18, 18, 1, 115200, fc612c0afeae3b6576b5ee2f3f119832
0, 19, 19, 1, 115200, 97074fe5a0b6e7e8470729654092e56c
0, 20, 20, 1, 115200, 8cf9337201065335b3aa4da21dc9b37a
0, 21, 21, 1, 115200, 93ff3589294cc0673af3daee1e7fe42a
0, 22, 22, 1, 115200, c0b6fd870a022f374f9d6c697e8e293d
0, 23, 23, 1, 115200, bc4638ff7036b323c39a948a6407695d