[FFmpeg-devel] [PATCH] avformat/movenc: fix assert failure in get_cluster_duration()

[FFmpeg-devel] [PATCH] avformat/movenc: fix assert failure in get_cluster_duration()

[Zhao Zhili]

When editlist is disabled, the workaournd method of shift dts to
zero and increase the first sample duration doesn't work if the
timestamp is larger than mp4 spec restriction (e.g., sample_delta
in stts entry). Further more, it triggers get_cluster_duration()
assert failure. This patch will drop large offsets between
multiple tracks.
---
 libavformat/movenc.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index 0f912dd012..dd92c0f26d 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -5917,7 +5917,18 @@ int ff_mov_write_packet(AVFormatContext *s, AVPacket *pkt)
          * to signal the difference in starting time without an edit list.
          * Thus move the timestamp for this first sample to 0, increasing
          * its duration instead. */
-        trk->cluster[trk->entry].dts = trk->start_dts = 0;
+        if (pkt->dts < INT32_MAX) {
+            trk->cluster[trk->entry].dts = trk->start_dts = 0;
+        } else {
+            /* Impossible to write a sample duration >= UINT32_MAX.
+             * Use INT32_MAX as a tight restriction.
+             */
+            trk->start_dts = pkt->dts;
+            av_log(s, AV_LOG_WARNING,
+                   "Track %d starts with a nonzero dts %" PRId64
+                   " which will be shifted to zero\n",
+                   pkt->stream_index, pkt->dts);
+        }
     }
     if (trk->start_dts == AV_NOPTS_VALUE) {
         trk->start_dts = pkt->dts;
-- 
2.31.1

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[FFmpeg-devel] [PATCH 2/2] avformat/movenc: add missing timestamp check when peek from interleave queues

[Zhao Zhili]

---
 libavformat/movenc.c | 80 +++++++++++++++++++++++++-------------------
 1 file changed, 45 insertions(+), 35 deletions(-)

diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index dd92c0f26d..3f35d2939f 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -5403,6 +5403,45 @@ static int mov_write_squashed_packets(AVFormatContext *s)
     return 0;
 }
 
+static int check_pkt_time(AVFormatContext *s, int stream_index,
+                          int64_t *pkt_pts, int64_t *pkt_dts,
+                          int64_t *pkt_duration) {
+    MOVMuxContext *mov = s->priv_data;
+    MOVTrack *trk = &mov->tracks[stream_index];
+    int64_t ref;
+    uint64_t duration;
+
+    if (trk->entry) {
+        ref = trk->cluster[trk->entry - 1].dts;
+    } else if (   trk->start_dts != AV_NOPTS_VALUE
+               && !trk->frag_discont) {
+        ref = trk->start_dts + trk->track_duration;
+    } else
+        ref = *pkt_dts; // Skip tests for the first packet
+
+    if (trk->dts_shift != AV_NOPTS_VALUE) {
+        /* With negative CTS offsets we have set an offset to the DTS,
+         * reverse this for the check. */
+        ref -= trk->dts_shift;
+    }
+
+    duration = *pkt_dts - ref;
+    if (*pkt_dts < ref || duration >= INT_MAX) {
+        av_log(s, AV_LOG_ERROR, "Application provided duration: %"PRId64" / timestamp: %"PRId64" is out of range for mov/mp4 format\n",
+               duration, *pkt_dts
+        );
+
+        *pkt_dts = ref + 1;
+        *pkt_pts = AV_NOPTS_VALUE;
+    }
+
+    if (*pkt_duration < 0 || *pkt_duration > INT_MAX) {
+        av_log(s, AV_LOG_ERROR, "Application provided duration: %"PRId64" is invalid\n", *pkt_duration);
+        return AVERROR(EINVAL);
+    }
+    return 0;
+}
+
 static int mov_flush_fragment(AVFormatContext *s, int force)
 {
     MOVMuxContext *mov = s->priv_data;
@@ -5429,12 +5468,15 @@ static int mov_flush_fragment(AVFormatContext *s, int force)
         if (!track->end_reliable) {
             const AVPacket *pkt = ff_interleaved_peek(s, i);
             if (pkt) {
-                int64_t offset, dts, pts;
+                int64_t offset, dts, pts, duration;
                 ff_get_muxer_ts_offset(s, i, &offset);
                 pts = pkt->pts + offset;
                 dts = pkt->dts + offset;
+                duration = pkt->duration;
                 if (track->dts_shift != AV_NOPTS_VALUE)
                     dts += track->dts_shift;
+                if (check_pkt_time(s, pkt->stream_index, &pts, &dts, &duration))
+                    continue;
                 track->track_duration = dts - track->start_dts;
                 if (pts != AV_NOPTS_VALUE)
                     track->end_pts = pts;
@@ -5627,40 +5669,8 @@ static int mov_auto_flush_fragment(AVFormatContext *s, int force)
 
 static int check_pkt(AVFormatContext *s, AVPacket *pkt)
 {
-    MOVMuxContext *mov = s->priv_data;
-    MOVTrack *trk = &mov->tracks[pkt->stream_index];
-    int64_t ref;
-    uint64_t duration;
-
-    if (trk->entry) {
-        ref = trk->cluster[trk->entry - 1].dts;
-    } else if (   trk->start_dts != AV_NOPTS_VALUE
-               && !trk->frag_discont) {
-        ref = trk->start_dts + trk->track_duration;
-    } else
-        ref = pkt->dts; // Skip tests for the first packet
-
-    if (trk->dts_shift != AV_NOPTS_VALUE) {
-        /* With negative CTS offsets we have set an offset to the DTS,
-         * reverse this for the check. */
-        ref -= trk->dts_shift;
-    }
-
-    duration = pkt->dts - ref;
-    if (pkt->dts < ref || duration >= INT_MAX) {
-        av_log(s, AV_LOG_ERROR, "Application provided duration: %"PRId64" / timestamp: %"PRId64" is out of range for mov/mp4 format\n",
-            duration, pkt->dts
-        );
-
-        pkt->dts = ref + 1;
-        pkt->pts = AV_NOPTS_VALUE;
-    }
-
-    if (pkt->duration < 0 || pkt->duration > INT_MAX) {
-        av_log(s, AV_LOG_ERROR, "Application provided duration: %"PRId64" is invalid\n", pkt->duration);
-        return AVERROR(EINVAL);
-    }
-    return 0;
+    return check_pkt_time(s, pkt->stream_index, &pkt->pts, &pkt->dts,
+                          &pkt->duration);
 }
 
 int ff_mov_write_packet(AVFormatContext *s, AVPacket *pkt)
-- 
2.31.1

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