[FFmpeg-devel] [PATCH] cuvid: Always calculate second field PTS from frame rate

[Miroslav Slugeň]

It is much more robust solution to always calculate second field (when 
deinterlacing) PTS from frame rate, then relating on previous PTS, 
because if there are B frames in input and some video frames are 
corrupted (dropped) it will calculate wrong PTS for second field and 
could hang on encoding in do_video_out.

--
Miroslav Slugeň






>From f8a19eb5fb82fee0cce1e1d7248bec57bdea08ac Mon Sep 17 00:00:00 2001
From: Miroslav Slugen <thunde...@email.cz>
Date: Wed, 8 Feb 2017 23:26:28 +0100
Subject: [PATCH 1/1] cuvid: Always calculate second field pts from frame rate

---
 libavcodec/cuvid.c | 13 +------------
 1 file changed, 1 insertion(+), 12 deletions(-)

diff --git a/libavcodec/cuvid.c b/libavcodec/cuvid.c
index 9b35476..19c024d 100644
--- a/libavcodec/cuvid.c
+++ b/libavcodec/cuvid.c
@@ -51,7 +51,6 @@ typedef struct CuvidContext
     AVFifoBuffer *frame_queue;
 
     int deint_mode;
-    int64_t prev_pts;
 
     int internal_error;
     int decoder_flushing;
@@ -512,14 +511,7 @@ static int cuvid_output_frame(AVCodecContext *avctx, AVFrame *frame)
             frame->pts = parsed_frame.dispinfo.timestamp;
 
         if (parsed_frame.second_field) {
-            if (ctx->prev_pts == INT64_MIN) {
-                ctx->prev_pts = frame->pts;
-                frame->pts += (avctx->pkt_timebase.den * avctx->framerate.den) / (avctx->pkt_timebase.num * avctx->framerate.num);
-            } else {
-                int pts_diff = (frame->pts - ctx->prev_pts) / 2;
-                ctx->prev_pts = frame->pts;
-                frame->pts += pts_diff;
-            }
+            frame->pts += (avctx->pkt_timebase.den * avctx->framerate.den) / (avctx->pkt_timebase.num * avctx->framerate.num);
         }
 
         /* CUVIDs opaque reordering breaks the internal pkt logic.
@@ -853,8 +845,6 @@ static av_cold int cuvid_decode_init(AVCodecContext *avctx)
     if (ret < 0)
         goto error;
 
-    ctx->prev_pts = INT64_MIN;
-
     if (!avctx->pkt_timebase.num || !avctx->pkt_timebase.den)
         av_log(avctx, AV_LOG_WARNING, "Invalid pkt_timebase, passing timestamps as-is.\n");
 
@@ -913,7 +903,6 @@ static void cuvid_flush(AVCodecContext *avctx)
     if (ret < 0)
         goto error;
 
-    ctx->prev_pts = INT64_MIN;
     ctx->decoder_flushing = 0;
 
     return;
-- 
2.1.4

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