[FFmpeg-devel] [PATCH] avformat/demux: in case of no timestamps, calculate dts based on previous dts and duration

Jan Ekström jeebjp at gmail.com
Fri May 5 14:31:23 EEST 2023


From: Martin Machalek <martin.machalek at 24i.com>

Adds DTS to packets which would otherwise break tbr calculation
within libavformat, as well as packet rate calculation in ffmpeg.

An example of such input would be an MPEG-TS stream where a whole
GOP is put into a single PES packet.

Co-authored-by: Jan Ekström <jan.ekstrom at 24i.com>

Signed-off-by: Jan Ekström <jan.ekstrom at 24i.com>
---
 libavformat/demux.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libavformat/demux.c b/libavformat/demux.c
index 06de71cd6e..9a4ab28679 100644
--- a/libavformat/demux.c
+++ b/libavformat/demux.c
@@ -1098,6 +1098,11 @@ static void compute_pkt_fields(AVFormatContext *s, AVStream *st,
     if (!onein_oneout)
         // This should happen on the first packet
         update_initial_timestamps(s, pkt->stream_index, pkt->dts, pkt->pts, pkt);
+
+    if (pkt->dts == AV_NOPTS_VALUE && !is_relative(sti->cur_dts) &&
+        sti->cur_dts != AV_NOPTS_VALUE && pkt->duration > 0)
+        pkt->dts = sti->cur_dts + pkt->duration;
+
     if (pkt->dts > sti->cur_dts)
         sti->cur_dts = pkt->dts;
 
-- 
2.40.1



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