I'm trying to setup an encode/decode pair across our corporate wan with the least amount of delay as possible.
So far I've been able to get the delay down using -probesize but we've found any value under 31000 causes the audio to stop. Also when using any value under 31000 we have to start the decoder first and then the encoder in order to be able to connect the video.
Getting these errors:
[mpegts @ 0x55bd17ba22c0] Stream #0: not enough frames to estimate rate; consider increasing probesize
[mpegts @ 0x55bd17ba22c0] Could not find codec parameters for stream 1 (Audio: aac ([15][0][0][0] / 0x000F), 0 channels): unspecified sample format
Consider increasing the value for the 'analyzeduration' (0) and 'probesize' (30000) options
Is it possible to use the low probesize values but still keep audio?
decoder
ffmpeg -probesize 31000 -i udp://decoderIP:8080 -f decklink -pix_fmt uyvy422 'DeckLink SDI (1)'
encoder
ffmpeg -probesize 31000 -f decklink -video_input 'sdi' -i 'DeckLink SDI (1)' -c:v libx264 -preset veryfast -tune zerolatency -bf 0 -c:a aac -f mpegts udp://decoderIP:8080
encoder:~$ ffmpeg -probesize 30000 -f decklink -video_input 'sdi' -i 'DeckLink SDI (1 )' -c:v libx264 -preset veryfast -tune zerolatency -bf 0 -c:a aac -f mpegts udp://decoderIP:8080
ffmpeg version 6.0 Copyright (c) 2000-2023 the FFmpeg developers
built with gcc 11 (Ubuntu 11.4.0-1ubuntu1~22.04)
configuration: --prefix=/home/supervisor/ffmpeg_build --pkg-config-flags=--static --extra-cflags='-I /home/supervisor/ffmpeg_build/include -I/home/supervisor/ffmpeg_sources/BMD_SDK/include' --extra-ldfla gs=-L/home/supervisor/ffmpeg_build/lib --extra-libs='-lpthread -lm' --bindir=/home/supervisor/bin --en able-gpl --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-nonfree --enable-deckli nk --enable-libsrt
libavutil 58. 2.100 / 58. 2.100
libavcodec 60. 3.100 / 60. 3.100
libavformat 60. 3.100 / 60. 3.100
libavdevice 60. 1.100 / 60. 1.100
libavfilter 9. 3.100 / 9. 3.100
libswscale 7. 1.100 / 7. 1.100
libswresample 4. 10.100 / 4. 10.100
libpostproc 57. 1.100 / 57. 1.100
[decklink @ 0x5558d076d480] Autodetected the input mode
[decklink @ 0x5558d076d480] Found Decklink mode 1280 x 720 with rate 59.94
Guessed Channel Layout for Input Stream #0.0 : stereo
Input #0, decklink, from 'DeckLink SDI (1)':
Duration: N/A, start: 0.000000, bitrate: 885388 kb/s
Stream #0:0: Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s
Stream #0:1: Video: rawvideo (UYVY / 0x59565955), uyvy422(progressive), 1280x720, 883852 kb/s, 59.94 tbr, 1000k tbn
Stream mapping:
Stream #0:1 -> #0:0 (rawvideo (native) -> h264 (libx264))
Stream #0:0 -> #0:1 (pcm_s16le (native) -> aac (native))
Press [q] to stop, [?] for help
[libx264 @ 0x5558d07854c0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 0x5558d07854c0] profile High 4:2:2, level 3.2, 4:2:2, 8-bit
Output #0, mpegts, to 'udp://decoderIP:8080':
Metadata:
encoder : Lavf60.3.100
Stream #0:0: Video: h264, yuv422p(tv, progressive), 1280x720, q=2-31, 59.94 fps, 90k tbn
Metadata:
encoder : Lavc60.3.100 libx264
Side data:
cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
Stream #0:1: Audio: aac (LC), 48000 Hz, stereo, fltp, 128 kb/s
Metadata:
encoder : Lavc60.3.100 aac
frame=187346 fps= 60 q=28.0 Lsize= 756972kB time=00:52:05.53 bitrate=1984.0kbits/s speed= 1x
video:657834kB audio:46939kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 7.4066 71%
[libx264 @ 0x5558d07854c0] frame I:780 Avg QP:21.84 size: 49451
[libx264 @ 0x5558d07854c0] frame P:186566 Avg QP:24.64 size: 3404
[libx264 @ 0x5558d07854c0] mb I I16..4: 26.6% 46.4% 27.0%
[libx264 @ 0x5558d07854c0] mb P I16..4: 3.3% 2.1% 0.2% P16..4: 14.1% 3.1% 0.9% 0.0% 0.0% s kip:76.3%
[libx264 @ 0x5558d07854c0] 8x8 transform intra:37.6% inter:37.8%
[libx264 @ 0x5558d07854c0] coded y,uvDC,uvAC intra: 24.8% 59.9% 10.9% inter: 2.5% 7.7% 0.2%
[libx264 @ 0x5558d07854c0] i16 v,h,dc,p: 41% 44% 12% 4%
[libx264 @ 0x5558d07854c0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 14% 26% 40% 3% 3% 3% 3% 3% 4%
[libx264 @ 0x5558d07854c0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 27% 41% 10% 4% 4% 4% 4% 4% 3%
[libx264 @ 0x5558d07854c0] i8c dc,h,v,p: 49% 29% 18% 5%
[libx264 @ 0x5558d07854c0] Weighted P-Frames: Y:0.4% UV:0.3%
[libx264 @ 0x5558d07854c0] kb/s:1724.16
[aac @ 0x5558d07869c0] Qavg: 8963.231
Exiting normally, received signal 2.
decoder:~$ ffmpeg -probesize 30000 -i udp://deciderIP:8080 -f decklink -pix_fmt uyvy422 'DeckLink SDI (1)'
ffmpeg version 6.0 Copyright (c) 2000-2023 the FFmpeg developers
built with gcc 11 (Ubuntu 11.4.0-1ubuntu1~22.04)
configuration: --prefix=/home/supervisor/ffmpeg_build --pkg-config-flags=--static --extra-cflags='-I/home/supervisor/ffmpeg_build/include -I/home/supervisor/ffmpeg_sources/BMD_SDK/include' --extra-ldflags=-L/home/supervisor/ffmpeg_build/lib --extra-libs='-lpthread -lm' --bindir=/home/supervisor/bin --enable-gpl --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-nonfree --enable-decklink --enable-libsrt
libavutil 58. 2.100 / 58. 2.100
libavcodec 60. 3.100 / 60. 3.100
libavformat 60. 3.100 / 60. 3.100
libavdevice 60. 1.100 / 60. 1.100
libavfilter 9. 3.100 / 9. 3.100
libswscale 7. 1.100 / 7. 1.100
libswresample 4. 10.100 / 4. 10.100
libpostproc 57. 1.100 / 57. 1.100
[mpegts @ 0x55bd17ba22c0] Stream #0: not enough frames to estimate rate; consider increasing probesize
[mpegts @ 0x55bd17ba22c0] Could not find codec parameters for stream 1 (Audio: aac ([15][0][0][0] / 0x000F), 0 channels): unspecified sample format
Consider increasing the value for the 'analyzeduration' (0) and 'probesize' (30000) options
Input #0, mpegts, from 'udp://decoderIP:8080':
Duration: N/A, start: 1.421333, bitrate: N/A
Program 1
Metadata:
service_name : Service01
service_provider: FFmpeg
Stream #0:0[0x100]: Video: h264 (High 4:2:2) ([27][0][0][0] / 0x001B), yuv422p(progressive), 1280x720, 59.94 tbr, 90k tbn
Stream #0:1[0x101]: Audio: aac ([15][0][0][0] / 0x000F), 0 channels
Stream mapping:
Stream #0:0 -> #0:0 (h264 (native) -> wrapped_avframe (native))
Press [q] to stop, [?] for help
[decklink @ 0x55bd17be2000] Found Decklink mode 1280 x 720 with rate 59.94
Output #0, decklink, to 'DeckLink SDI (1)':
Metadata:
encoder : Lavf60.3.100
Stream #0:0: Video: wrapped_avframe, uyvy422(tv, progressive), 1280x720, q=2-31, 200 kb/s, 59.94 fps, 59.94 tbn
Metadata:
encoder : Lavc60.3.100 wrapped_avframe
frame=187328 fps= 60 q=-0.0 size=N/A time=00:52:05.25 bitrate=N/A speed= 1x 0x
