[FFmpeg-user] audio video out of sync

[Matthew Reus]

Hello ,

I m taking a raw video from a box using* HDMI TO SDI* convert using *Decklink
quad 2 *card , the stream will work fine for an hour . But after an hour
the audio video goes oout of sync .


*ffmpeg -async 1 -vsync 1 -f decklink -i 'DeckLink Quad (3)@11' -pix_fmt
yuv420p -r 30 -s 1920x1080 -vf "yadif=0:-1:0" -c:v h264_nvenc -gpu 0 -b:v
4000k -c:a aac -filter:a "volume=4" -aspect 16:9 -ac 2 -f flv
'rtmp://admin:netaccess@192.168.0.44:1935/nettv/SABHD.stream
<http://admin:netaccess@192.168.0.44:1935/nettv/SABHD.stream>' *

and here is my log

ffmpeg version 4.1 Copyright (c) 2000-2018 the FFmpeg developers
  built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.10) 20160609
  configuration: --prefix=/root/ffmpeg_build --pkg-config-flags=--static
--extra-cflags=-I/root/ffmpeg_build/include
--extra-ldflags=-L/root/ffmpeg_build/lib --extra-libs='-lpthread -lm'
--bindir=/root/bin --enable-gpl --enable-libass --enable-libfdk-aac
--enable-libfreetype --enable-libmp3lame --enable-libvorbis --enable-libvpx
--enable-libx264 --enable-libx265 --enable-decklink
--extra-cflags=-I/usr/local/sdk/Linux/include/
--extra-ldflags=-L/usr/local/sdk/Linux/include/ --enable-nvenc
--extra-cflags=-I../cudautils --extra-ldflags=-L../cudautils
--enable-nonfree
  libavutil      56. 22.100 / 56. 22.100
  libavcodec     58. 35.100 / 58. 35.100
  libavformat    58. 20.100 / 58. 20.100
  libavdevice    58.  5.100 / 58.  5.100
  libavfilter     7. 40.101 /  7. 40.101
  libswscale      5.  3.100 /  5.  3.100
  libswresample   3.  3.100 /  3.  3.100
  libpostproc    55.  3.100 / 55.  3.100
[decklink @ 0x3e23300] The @mode syntax is deprecated and will be removed.
Please use the -format_code option.
[decklink @ 0x3e23300] Found Decklink mode 1920 x 1080 with rate 25.00(i)
[decklink @ 0x3e23300] Frame received (#1) - No input signal detected -
Frames dropped 1
Guessed Channel Layout for Input Stream #0.0 : stereo
Input #0, decklink, from 'DeckLink Quad (3)@11':
  Duration: N/A, start: 0.000000, bitrate: 830976 kb/s
    Stream #0:0: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
    Stream #0:1: Video: rawvideo (UYVY / 0x59565955), uyvy422(top first),
1920x1080, 829440 kb/s, 25 tbr, 1000k tbn, 1000k tbc
[rtmp @ 0x3e85200] Ignoring unsupported var reason
Stream mapping:
  Stream #0:1 -> #0:0 (rawvideo (native) -> h264 (h264_nvenc))
  Stream #0:0 -> #0:1 (pcm_s16le (native) -> aac (native))
Press [q] to stop, [?] for help
[decklink @ 0x3e23300] Frame received (#11) - Input returned - Frames
dropped 2
-async is forwarded to lavfi similarly to -af
aresample=async=1:min_hard_comp=0.100000:first_pts=0.
Output #0, flv, to 'rtmp://
admin:netaccess at 192.168.0.44:1935/test/SABHD.stream':
  Metadata:
    encoder         : Lavf58.20.100
    Stream #0:0: Video: h264 (h264_nvenc) (Main) ([7][0][0][0] / 0x0007),
yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], q=-1--1, 4000 kb/s, 30 fps, 1k tbn,
30 tbc
    Metadata:
      encoder         : Lavc58.35.100 h264_nvenc
    Side data:
      cpb: bitrate max/min/avg: 0/0/4000000 buffer size: 8000000 vbv_delay:
-1
    Stream #0:1: Audio: aac (LC) ([10][0][0][0] / 0x000A), 48000 Hz,
stereo, fltp, 128 kb/s
    Metadata:
      encoder         : Lavc58.35.100 aac
size=   23657kB time=00:00:44.82 bitrate=4323.8kbits/s dup=225 drop=0
speed=   1x