[FFmpeg-cvslog] Revert "avcodec/nvenc: fix b-frame DTS behavior with fractional framerates"
Timo Rothenpieler
git at videolan.org
Thu Jun 15 02:02:37 EEST 2023
ffmpeg | branch: master | Timo Rothenpieler <timo at rothenpieler.org> | Thu Jun 15 00:45:44 2023 +0200| [ac7c265b33b52f914ebe05e581bbe9343eca1186] | committer: Timo Rothenpieler
Revert "avcodec/nvenc: fix b-frame DTS behavior with fractional framerates"
This reverts commit 9a245bdf5d7860b8bc5e5c21a105a075925b719a.
This commit basically broke all samples with fractional framerates,
rather than fixing them.
I at this point do not understand the original issue anymore, and I'm
not sure how this slipped my initial testing.
All my test samples must have happened to have a simple timebase.
The actual dts values pretty much always are just a simple chain of
1,2,3,4,5,... Or maybe slightly bigger steps. Each increase by one means
an advance in time by one unit of the timebase.
So a fractional framerate/timebase is already not an issue.
So with this patch applied, the calculation might end up substracting
huge values (1001 is a common one) from the dts, which would be an
offset of that many frames, not of that many fractions of a second.
This broke at least muxing into mp4, if the sample happened to have a
fractional framerate.
I do not thing the original issue this patch tried to fix existed in the
first place, so it can be reverted without further consequences.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=ac7c265b33b52f914ebe05e581bbe9343eca1186
---
libavcodec/nvenc.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/libavcodec/nvenc.c b/libavcodec/nvenc.c
index 50371d6336..7874cb887b 100644
--- a/libavcodec/nvenc.c
+++ b/libavcodec/nvenc.c
@@ -2285,11 +2285,10 @@ static int nvenc_set_timestamp(AVCodecContext *avctx,
if (avctx->codec_descriptor->props & AV_CODEC_PROP_REORDER) {
FF_DISABLE_DEPRECATION_WARNINGS
pkt->dts = dts -
- FFMAX(ctx->encode_config.frameIntervalP - 1, 0)
#if FF_API_TICKS_PER_FRAME
- * FFMAX(avctx->ticks_per_frame, 1)
+ FFMAX(avctx->ticks_per_frame, 1) *
#endif
- * FFMAX(avctx->time_base.num, 1);
+ FFMAX(ctx->encode_config.frameIntervalP - 1, 0);
FF_ENABLE_DEPRECATION_WARNINGS
} else {
pkt->dts = pkt->pts;
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