[FFmpeg-devel] [PATCH] lavf/mov.c: Parse upto 2 keyframes after the edit list end in mov_fix_index.

[Sasi Inguva]

Partially fixes t/6699.
---
 libavformat/mov.c  | 32 +++++++++++++++++++++-----------
 tests/fate/mov.mak |  4 ++++
 2 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/libavformat/mov.c b/libavformat/mov.c
index 60f0228e2d..e716e5ba9e 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -3232,6 +3232,7 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
     int packet_skip_samples = 0;
     MOVIndexRange *current_index_range;
     int i;
+    int found_keyframe_after_edit = 0;
 
     if (!msc->elst_data || msc->elst_count <= 0 || nb_old <= 0) {
         return;
@@ -3347,6 +3348,7 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
 
         // Iterate over index and arrange it according to edit list
         edit_list_start_encountered = 0;
+        found_keyframe_after_edit = 0;
         for (; current < e_old_end; current++, index++) {
             // check  if frame outside edit list mark it for discard
             frame_duration = (current + 1 <  e_old_end) ?
@@ -3459,18 +3461,26 @@ static void mov_fix_index(MOVContext *mov, AVStream *st)
             }
 
             // Break when found first key frame after edit entry completion
-            if (((curr_cts + frame_duration) >= (edit_list_duration + edit_list_media_time)) &&
+            if ((curr_cts + frame_duration >= (edit_list_duration + edit_list_media_time)) &&
                 ((flags & AVINDEX_KEYFRAME) || ((st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO)))) {
-
-                if (ctts_data_old && ctts_sample_old != 0) {
-                    if (add_ctts_entry(&msc->ctts_data, &msc->ctts_count,
-                                       &msc->ctts_allocated_size,
-                                       ctts_sample_old - edit_list_start_ctts_sample,
-                                       ctts_data_old[ctts_index_old].duration) == -1) {
-                        av_log(mov->fc, AV_LOG_ERROR, "Cannot add CTTS entry %"PRId64" - {%"PRId64", %d}\n",
-                               ctts_index_old, ctts_sample_old - edit_list_start_ctts_sample,
-                               ctts_data_old[ctts_index_old].duration);
-                        break;
+                if (ctts_data_old) {
+                    // If we have CTTS and this is the the first keyframe after edit elist,
+                    // wait for one more, because there might be trailing B-frames after this I-frame
+                    // that do belong to the edit.
+                    if (st->codecpar->codec_type != AVMEDIA_TYPE_AUDIO && found_keyframe_after_edit == 0) {
+                        found_keyframe_after_edit = 1;
+                        continue;
+                    }
+                    if (ctts_sample_old != 0) {
+                        if (add_ctts_entry(&msc->ctts_data, &msc->ctts_count,
+                                           &msc->ctts_allocated_size,
+                                           ctts_sample_old - edit_list_start_ctts_sample,
+                                           ctts_data_old[ctts_index_old].duration) == -1) {
+                            av_log(mov->fc, AV_LOG_ERROR, "Cannot add CTTS entry %"PRId64" - {%"PRId64", %d}\n",
+                                   ctts_index_old, ctts_sample_old - edit_list_start_ctts_sample,
+                                   ctts_data_old[ctts_index_old].duration);
+                            break;
+                        }
                     }
                 }
                 break;
diff --git a/tests/fate/mov.mak b/tests/fate/mov.mak
index 6815e4feca..e444b1459d 100644
--- a/tests/fate/mov.mak
+++ b/tests/fate/mov.mak
@@ -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-elst-ends-betn-b-and-i \
 
 FATE_MOV_FFPROBE = fate-mov-aac-2048-priming \
                    fate-mov-zombie \
@@ -41,6 +42,9 @@ fate-mov-1elist-ends-last-bframe: CMD = framemd5 -i $(TARGET_SAMPLES)/mov/mov-1e
 # Makes sure that we handle timestamps of packets in case of multiple edit lists with one of them ending on a B-frame correctly.
 fate-mov-2elist-elist1-ends-bframe: CMD = framemd5 -i $(TARGET_SAMPLES)/mov/mov-2elist-elist1-ends-bframe.mov
 
+# Makes sure that if edit list ends on a B-frame but before the I-frame, then we output the B-frame but discard the I-frame.
+fate-mov-elst-ends-betn-b-and-i: CMD = framemd5 -i $(TARGET_SAMPLES)/mov/elst_ends_betn_b_and_i.mp4
+
 # Makes sure that we handle edit lists and start padding correctly.
 fate-mov-440hz-10ms: CMD = framemd5 -i $(TARGET_SAMPLES)/mov/440hz-10ms.m4a
 
-- 
2.15.0.403.gc27cc4dac6-goog