[FFmpeg-devel] [PATCH] lavf/utils: Fix DTS for short H264 streams.

[Sasi Inguva]

Fill DTS if all packets have been read in avformat_find_stream_info, and still
has_decode_delay_been_guessed returns false.

Signed-off-by: Sasi Inguva <isasi at google.com>
---
 libavformat/utils.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/libavformat/utils.c b/libavformat/utils.c
index 5f48de1..f22309d 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -877,6 +877,7 @@ static int has_decode_delay_been_guessed(AVStream *st)
        avpriv_h264_has_num_reorder_frames(st->codec) == st->codec->has_b_frames)
         return 1;
 #endif
+
     if (st->codec->has_b_frames<3)
         return st->nb_decoded_frames >= 7;
     else if (st->codec->has_b_frames<4)
@@ -3165,6 +3166,7 @@ int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
     int64_t max_stream_analyze_duration;
     int64_t max_subtitle_analyze_duration;
     int64_t probesize = ic->probesize;
+    int eof_reached = 0;
 
     flush_codecs = probesize > 0;
 
@@ -3331,6 +3333,7 @@ int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
 
         if (ret < 0) {
             /* EOF or error*/
+            eof_reached = 1;
             break;
         }
 
@@ -3454,6 +3457,40 @@ int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
         count++;
     }
 
+    if (eof_reached && ic->internal->packet_buffer) {
+        int stream_index;
+        for (stream_index = 0; stream_index < ic->nb_streams; stream_index++) {
+            AVPacketList *pktl = ic->internal->packet_buffer;
+            int64_t pts_buffer[MAX_REORDER_DELAY+1];
+
+            // EOF already reached while reading the stream above.
+            // So continue with reoordering DTS with whatever delay we have.
+            int codec_delay = st->codec->has_b_frames;
+
+            st = ic->streams[stream_index];
+
+            if (st->codec->codec_id != AV_CODEC_ID_H264 ||
+                has_decode_delay_been_guessed(st)) {
+                continue;
+            }
+
+
+            for (; pktl; pktl = get_next_pkt(ic, st, pktl)) {
+                if (pktl->pkt.stream_index != stream_index)
+                    continue;
+
+                if (pktl->pkt.pts != AV_NOPTS_VALUE && codec_delay <= MAX_REORDER_DELAY) {
+                    int j;
+                    pts_buffer[0] = pktl->pkt.pts;
+                    for (j = 0; j < codec_delay && pts_buffer[j] > pts_buffer[j + 1]; j++)
+                      FFSWAP(int64_t, pts_buffer[j], pts_buffer[j + 1]);
+
+                    pktl->pkt.dts = select_from_pts_buffer(st, pts_buffer, pktl->pkt.dts);
+                }
+            }
+        }
+    }
+
     if (flush_codecs) {
         AVPacket empty_pkt = { 0 };
         int err = 0;
-- 
2.7.0.rc3.207.g0ac5344