Estou transmitindo um vídeo para um mecanismo de streaming (nginx-rtmp) usando o ffmpeg usando o seguinte comando:
ffmpeg -re -fflags +genpts -stream_loop -1 -i Sintel.mp4 -c copy -f flv rtmp://stream-engine/myStream
No entanto, quando estou fazendo um ffprobe desse fluxo, diretamente para o mecanismo de streaming, às vezes não há vídeo no fluxo.
O comando para testar o fluxo: ffprobe -loglevel 'debug' rtmp://stream-engine/mystream
95% Eu recebo a seguinte saída:
ffprobe version 3.0.2 Copyright (c) 2007-2016 the FFmpeg developers
built with Apple LLVM version 8.0.0 (clang-800.0.38)
configuration: --prefix=/usr/local/Cellar/ffmpeg/3.0.2 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-opencl --enable-libx264 --enable-libmp3lame --enable-libxvid --enable-libvorbis --enable-libvpx --enable-vda
libavutil 55. 17.103 / 55. 17.103
libavcodec 57. 24.102 / 57. 24.102
libavformat 57. 25.100 / 57. 25.100
libavdevice 57. 0.101 / 57. 0.101
libavfilter 6. 31.100 / 6. 31.100
libavresample 3. 0. 0 / 3. 0. 0
libswscale 4. 0.100 / 4. 0.100
libswresample 2. 0.101 / 2. 0.101
libpostproc 54. 0.100 / 54. 0.100
[rtmp @ 0x7ff57e4028a0] No default whitelist set
[tcp @ 0x7ff57e402d40] No default whitelist set
[rtmp @ 0x7ff57e4028a0] Handshaking...
[rtmp @ 0x7ff57e4028a0] Type answer 3
[rtmp @ 0x7ff57e4028a0] Server version 13.14.10.13
[rtmp @ 0x7ff57e4028a0] Proto = rtmp, path = /source/myStream, app = source, fname = myStream
[rtmp @ 0x7ff57e4028a0] Server bandwidth = 5000000
[rtmp @ 0x7ff57e4028a0] Client bandwidth = 5000000
[rtmp @ 0x7ff57e4028a0] New incoming chunk size = 4096
[rtmp @ 0x7ff57e4028a0] Creating stream...
[rtmp @ 0x7ff57e4028a0] Sending play command for 'myStream'
[flv @ 0x7ff57f002e00] Format flv probed with size=2048 and score=100
[flv @ 0x7ff57f002e00] Before avformat_find_stream_info() pos: 13 bytes read:2266 seeks:0
[flv @ 0x7ff57f002e00] Unknown type |RtmpSampleAccess
[flv @ 0x7ff57f002e00] video stream discovered after head already parsed
[h264 @ 0x7ff580000000] no picture
[flv @ 0x7ff57f002e00] All info found
[flv @ 0x7ff57f002e00] rfps: 23.750000 0.014474
[flv @ 0x7ff57f002e00] rfps: 23.833333 0.006451
Last message repeated 1 times
[flv @ 0x7ff57f002e00] rfps: 23.916667 0.001640
Last message repeated 1 times
[flv @ 0x7ff57f002e00] rfps: 24.000000 0.000043
[flv @ 0x7ff57f002e00] rfps: 24.083333 0.001659
Last message repeated 1 times
[flv @ 0x7ff57f002e00] rfps: 24.166667 0.006488
Last message repeated 1 times
[flv @ 0x7ff57f002e00] rfps: 24.250000 0.014530
[flv @ 0x7ff57f002e00] rfps: 48.000000 0.000173
[flv @ 0x7ff57f002e00] rfps: 120.000000 0.001079
[flv @ 0x7ff57f002e00] rfps: 240.000000 0.004316
[flv @ 0x7ff57f002e00] rfps: 23.976024 0.000173
Last message repeated 1 times
[flv @ 0x7ff57f002e00] rfps: 47.952048 0.000694
Last message repeated 1 times
[flv @ 0x7ff57f002e00] After avformat_find_stream_info() pos: 345943 bytes read:345943 seeks:0 frames:256
Input #0, flv, from 'rtmp://stream-engine/myStream':
Metadata:
Server : NGINX RTMP (github.com/arut/nginx-rtmp-module)
displayWidth : 1280
displayHeight : 544
fps : 24
profile :
level :
Duration: 00:00:00.00, start: 186.878000, bitrate: N/A
Stream #0:0, 215, 1/1000: Audio: aac (LC), 48000 Hz, 5.1, fltp, 128 kb/s
Stream #0:1, 41, 1/1000: Video: h264 (High), 4 reference frames, yuv420p(left), 1280x544 [SAR 1:1 DAR 40:17], 1/48, 24.42 fps, 24 tbr, 1k tbn, 48 tbc
detected 4 logical cores
[AVIOContext @ 0x7ff57e60cec0] Statistics: 345943 bytes read, 0 seeks
[rtmp @ 0x7ff57e4028a0] Deleting stream...
Que está tudo bem, recebo faixas de vídeo e áudio.
5% das vezes recebo o seguinte:
ffprobe version 3.0.2 Copyright (c) 2007-2016 the FFmpeg developers
built with Apple LLVM version 8.0.0 (clang-800.0.38)
configuration: --prefix=/usr/local/Cellar/ffmpeg/3.0.2 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-opencl --enable-libx264 --enable-libmp3lame --enable-libxvid --enable-libvorbis --enable-libvpx --enable-vda
libavutil 55. 17.103 / 55. 17.103
libavcodec 57. 24.102 / 57. 24.102
libavformat 57. 25.100 / 57. 25.100
libavdevice 57. 0.101 / 57. 0.101
libavfilter 6. 31.100 / 6. 31.100
libavresample 3. 0. 0 / 3. 0. 0
libswscale 4. 0.100 / 4. 0.100
libswresample 2. 0.101 / 2. 0.101
libpostproc 54. 0.100 / 54. 0.100
[rtmp @ 0x7fe5cb407900] No default whitelist set
[tcp @ 0x7fe5cb408100] No default whitelist set
[rtmp @ 0x7fe5cb407900] Handshaking...
[rtmp @ 0x7fe5cb407900] Type answer 3
[rtmp @ 0x7fe5cb407900] Server version 13.14.10.13
[rtmp @ 0x7fe5cb407900] Proto = rtmp, path = /source/myStream, app = source, fname = myStream
[rtmp @ 0x7fe5cb407900] Server bandwidth = 5000000
[rtmp @ 0x7fe5cb407900] Client bandwidth = 5000000
[rtmp @ 0x7fe5cb407900] New incoming chunk size = 4096
[rtmp @ 0x7fe5cb407900] Creating stream...
[rtmp @ 0x7fe5cb407900] Sending play command for 'myStream'
[flv @ 0x7fe5cb800a00] Format flv probed with size=2048 and score=100
[flv @ 0x7fe5cb800a00] Before avformat_find_stream_info() pos: 13 bytes read:2288 seeks:0
[flv @ 0x7fe5cb800a00] Unknown type |RtmpSampleAccess
[flv @ 0x7fe5cb800a00] max_analyze_duration 5000000 reached at 5019000 microseconds st:0
[flv @ 0x7fe5cb800a00] After avformat_find_stream_info() pos: 87188 bytes read:87188 seeks:0 frames:241
Input #0, flv, from 'rtmp://stream-engine/myStream':
Metadata:
Server : NGINX RTMP (github.com/arut/nginx-rtmp-module)
displayWidth : 1280
displayHeight : 544
fps : 24
profile :
level :
Duration: 00:00:00.00, start: 343.593000, bitrate: N/A
Stream #0:0, 241, 1/1000: Audio: aac (LC), 48000 Hz, 5.1, fltp, 128 kb/s
[AVIOContext @ 0x7fe5cb604480] Statistics: 87188 bytes read, 0 seeks
[rtmp @ 0x7fe5cb407900] Deleting stream...
Nós tentamos muitas opções, muitos codificadores. Nós o reproduzimos com diferentes fontes de fluxo (ffmpeg, wowzaGoCoder, wirecast) e diferentes mecanismos de streaming (wowza, nginx-rtmp). Algumas configurações dificultam a reprodução, mas ainda acontece ...
Como pode ser que o mesmo fluxo possa ter uma faixa de vídeo "às vezes"? O que estamos perdendo? Como podemos torná-lo mais resistente a esse bug (muito frustrante)?
Editar:
Se gravarmos o fluxo, e se ele não detectar a trilha de vídeo, o registro exibirá após algum tempo que a trilha de vídeo foi detectada, mas como a gravação já começou sem ela, o fluxo gravado não tem trilha de vídeo. / p>
Registro da gravação de fluxo ffmpeg -loglevel debug -y -i rtmp://stream-engine/myStream -c copy -f flv output.flv :
ffmpeg version 3.0.2 Copyright (c) 2000-2016 the FFmpeg developers
built with Apple LLVM version 8.0.0 (clang-800.0.38)
configuration: --prefix=/usr/local/Cellar/ffmpeg/3.0.2 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-opencl --enable-libx264 --enable-libmp3lame --enable-libxvid --enable-libvorbis --enable-libvpx --enable-vda
libavutil 55. 17.103 / 55. 17.103
libavcodec 57. 24.102 / 57. 24.102
libavformat 57. 25.100 / 57. 25.100
libavdevice 57. 0.101 / 57. 0.101
libavfilter 6. 31.100 / 6. 31.100
libavresample 3. 0. 0 / 3. 0. 0
libswscale 4. 0.100 / 4. 0.100
libswresample 2. 0.101 / 2. 0.101
libpostproc 54. 0.100 / 54. 0.100
Splitting the commandline.
Reading option '-loglevel' ... matched as option 'loglevel' (set logging level) with argument 'debug'.
Reading option '-y' ... matched as option 'y' (overwrite output files) with argument '1'.
Reading option '-i' ... matched as input file with argument 'rtmp://stream-engine/myStream'.
Reading option '-c' ... matched as option 'c' (codec name) with argument 'copy'.
Reading option '-f' ... matched as option 'f' (force format) with argument 'flv'.
Reading option 'output.flv' ... matched as output file.
Finished splitting the commandline.
Parsing a group of options: global .
Applying option loglevel (set logging level) with argument debug.
Applying option y (overwrite output files) with argument 1.
Successfully parsed a group of options.
Parsing a group of options: input file rtmp://stream-engine/myStream.
Successfully parsed a group of options.
Opening an input file: rtmp://stream-engine/myStream.
[rtmp @ 0x7fa1a5d00c60] No default whitelist set
[tcp @ 0x7fa1a5c0dac0] No default whitelist set
[rtmp @ 0x7fa1a5d00c60] Handshaking...
[rtmp @ 0x7fa1a5d00c60] Type answer 3
[rtmp @ 0x7fa1a5d00c60] Server version 13.14.10.13
[rtmp @ 0x7fa1a5d00c60] Proto = rtmp, path = /source/S1IwVWndb, app = source, fname = S1IwVWndb
[rtmp @ 0x7fa1a5d00c60] Server bandwidth = 5000000
[rtmp @ 0x7fa1a5d00c60] Client bandwidth = 5000000
[rtmp @ 0x7fa1a5d00c60] New incoming chunk size = 4096
[rtmp @ 0x7fa1a5d00c60] Creating stream...
[rtmp @ 0x7fa1a5d00c60] Sending play command for 'S1IwVWndb'
[flv @ 0x7fa1a6801200] Format flv probed with size=2048 and score=100
[flv @ 0x7fa1a6801200] Before avformat_find_stream_info() pos: 13 bytes read:2271 seeks:0
[flv @ 0x7fa1a6801200] Unknown type |RtmpSampleAccess
[flv @ 0x7fa1a6801200] max_analyze_duration 5000000 reached at 5019000 microseconds st:0
[flv @ 0x7fa1a6801200] After avformat_find_stream_info() pos: 87184 bytes read:87184 seeks:0 frames:241
Input #0, flv, from 'rtmp://stream-engine/myStream':
Metadata:
Server : NGINX RTMP (github.com/arut/nginx-rtmp-module)
displayWidth : 1280
displayHeight : 544
fps : 24
profile :
level :
Duration: 00:00:00.00, start: 344.126000, bitrate: N/A
Stream #0:0, 241, 1/1000: Audio: aac (LC), 48000 Hz, 5.1, fltp, 128 kb/s
Successfully opened the file.
Parsing a group of options: output file output.flv.
Applying option c (codec name) with argument copy.
Applying option f (force format) with argument flv.
Successfully parsed a group of options.
Opening an output file: output.flv.
[file @ 0x7fa1a5c1cec0] Setting default whitelist 'file,crypto'
Successfully opened the file.
Output #0, flv, to 'output.flv':
Metadata:
Server : NGINX RTMP (github.com/arut/nginx-rtmp-module)
displayWidth : 1280
displayHeight : 544
fps : 24
profile :
level :
encoder : Lavf57.25.100
Stream #0:0, 0, 1/1000: Audio: aac (LC) ([10][0][0][0] / 0x000A), 48000 Hz, 5.1, 128 kb/s
Stream mapping:
Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
cur_dts is invalid (this is harmless if it occurs once at the start per stream)
[flv @ 0x7fa1a6801200] video stream discovered after head already parsed
[flv @ 0x7fa1a6801200] New video stream 0:1 at pos:144269 and DTS:352.667s
size= 371kB time=00:00:22.57 bitrate= 134.6kbits/s speed= 1.3x
video:0kB audio:353kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 5.082170%
Input file #0 (rtmp://stream-engine/myStream):
Input stream #0:0 (audio): 1058 packets read (361263 bytes);
Total: 1058 packets (361263 bytes) demuxed
Output file #0 (output.flv):
Output stream #0:0 (audio): 1058 packets muxed (361263 bytes);
Total: 1058 packets (361263 bytes) muxed
0 frames successfully decoded, 0 decoding errors
[AVIOContext @ 0x7fa1a5c1cf80] Statistics: 3 seeks, 1061 writeouts
[AVIOContext @ 0x7fa1a5d00fa0] Statistics: 2401247 bytes read, 0 seeks
[rtmp @ 0x7fa1a5d00c60] Deleting stream..
Obrigado ao comentário mulvya: Stream recebido não t tem trilha de vídeo consistente , aumentando o valor de analysisuration e o probesize dá mais chances ao ffmpeg de detectar todas as informações necessárias para processar corretamente o fluxo.
Valor padrão com base na documentação do ffmpeg: link são:
Qual fluxo de alta qualidade não é suficiente.