我正在尝试使用rtsp从CCTV DVR服务器（6个频道）复制视频。如何优化ffmpeg命令？
下面是配置：
ffmpeg版本：ffmpeg-4.1.4-win64-static 处理器：Intel Core i7-8650U @ 1.9 GHz 2.11 GHz 内存：16 GB
当我尝试从3个频道下载时，视频似乎可以正常下载，但是当我同时使用> = 4个频道时，来自频道1的视频将在大约5秒钟后被截断，并且输出文件要比该频道小得多2至4，第5通道视频输出没有问题。
例如这是根据通道的输出文件大小。
Channel 1 : 1.7 MB (truncated)
Channel 2 : 27.5 MB (approx 5 secs video loss in the beginning)
Channel 3 : 28.5 MB (approx 3-4 secs loss)
channel 4 : 29.5 MB (approx 2 secs loss)
Channel 5 : 30 MB (no issues found)
下面是我要用来下载的命令。
ffmpeg -rtsp_transport tcp -thread_queue_size 1024 -i rtsp://<input url 1> -thread_queue_size 1024 -i rtsp://<input url 2> -thread_queue_size 1024 -i rtsp://<input url 3> -thread_queue_size 1024 -i rtsp://<input url 4> -thread_queue_size 1024 -i rtsp://<input url 5> -map 0 -vcodec copy -t 60 -y outputfile1.mp4 -map 1 -vcodec copy -t 60 -y outputfile2.mp4 -map 2 -vcodec copy -t 60 -y outputfile3.mp4 -map 3 -vcodec copy -t 60 -y outputfile4.mp4 -map 4 -vcodec copy -t 60 -y outputfile5.mp4
下面是实际输出：
ffmpeg version 4.1.4 Copyright (c) 2000-2019 the FFmpeg developers
built with gcc 9.1.1 (GCC) 20190716
configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-amf --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth
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
Input #0, rtsp, from 'rtsp://<input url 1':
Metadata:
title : -
Duration: N/A, start: 0.080000, bitrate: N/A
Stream #0:0: Video: h264 (High), yuv420p(progressive), 1920x1080, 25 tbr, 90k tbn, 180k tbc
[udp @ 000001f27c6fffc0] 'circular_buffer_size' option was set but it is not supported on this build (pthread support is required)
[udp @ 000001f27c74f400] 'circular_buffer_size' option was set but it is not supported on this build (pthread support is required)
[rtsp @ 000001f27c721f40] max delay reached. need to consume packet
[rtsp @ 000001f27c721f40] RTP: missed 15 packets
[h264 @ 000001f27d627ac0] error while decoding MB 71 49, bytestream -6
[h264 @ 000001f27d627ac0] concealing 2258 DC, 2258 AC, 2258 MV errors in P frame
[h264 @ 000001f27d627ac0] Increasing reorder buffer to 1
Input #1, rtsp, from 'rtsp://<input url 2':
Metadata:
title : -
Duration: N/A, start: 0.040000, bitrate: N/A
Stream #1:0: Video: h264 (High), yuv420p(progressive), 1920x1080, 25 tbr, 90k tbn, 180k tbc
[udp @ 000001f27c6ffc40] 'circular_buffer_size' option was set but it is not supported on this build (pthread support is required)
[udp @ 000001f27d2dc180] 'circular_buffer_size' option was set but it is not supported on this build (pthread support is required)
[rtsp @ 000001f27d2db700] max delay reached. need to consume packet
[rtsp @ 000001f27d2db700] RTP: missed 15 packets
[h264 @ 000001f27d2dbd00] concealing 7337 DC, 7337 AC, 7337 MV errors in P frame
[h264 @ 000001f27d2dbd00] Increasing reorder buffer to 1
Input #2, rtsp, from '<input url 3':
Metadata:
title : -
Duration: N/A, start: 0.080000, bitrate: N/A
Stream #2:0: Video: h264 (High), yuv420p(progressive), 1920x1080, 25 tbr, 90k tbn, 180k tbc
[udp @ 000001f27c6ffd00] 'circular_buffer_size' option was set but it is not supported on this build (pthread support is required)
[udp @ 000001f27d302bc0] 'circular_buffer_size' option was set but it is not supported on this build (pthread support is required)
[rtsp @ 000001f27cfe9200] max delay reached. need to consume packet
[rtsp @ 000001f27cfe9200] RTP: missed 44 packets
[h264 @ 000001f27cfe6c40] error while decoding MB 41 24, bytestream -8
[h264 @ 000001f27cfe6c40] concealing 5288 DC, 5288 AC, 5288 MV errors in P frame
[h264 @ 000001f27cfe6c40] Increasing reorder buffer to 1
Input #3, rtsp, from '<input url 4':
Metadata:
title : -
Duration: N/A, start: 0.080000, bitrate: N/A
Stream #3:0: Video: h264 (High), yuv420p(progressive), 1920x1080, 25 tbr, 90k tbn, 180k tbc
[udp @ 000001f27cfe0940] 'circular_buffer_size' option was set but it is not supported on this build (pthread support is required)
[udp @ 000001f27dd1bec0] 'circular_buffer_size' option was set but it is not supported on this build (pthread support is required)
[rtsp @ 000001f27daaf040] max delay reached. need to consume packet
[rtsp @ 000001f27daaf040] RTP: missed 107 packets
[h264 @ 000001f27dc05040] concealing 1340 DC, 1340 AC, 1340 MV errors in P frame
[rtsp @ 000001f27daaf040] max delay reached. need to consume packet
[rtsp @ 000001f27daaf040] RTP: missed 28 packets
[h264 @ 000001f27dc05040] Increasing reorder buffer to 1
[h264 @ 000001f27dc05040] concealing 6961 DC, 6961 AC, 6961 MV errors in P frame
[rtsp @ 000001f27daaf040] max delay reached. need to consume packet
[rtsp @ 000001f27daaf040] RTP: missed 53 packets
[h264 @ 000001f27dc05040] error while decoding MB 16 40, bytestream -18
[h264 @ 000001f27dc05040] concealing 3393 DC, 3393 AC, 3393 MV errors in I frame
Input #4, rtsp, from 'rtsp://<input url 5':
Metadata:
title : -
Duration: N/A, start: 0.120000, bitrate: N/A
Stream #4:0: Video: h264 (High), yuv420p(progressive), 1920x1080, 25 tbr, 90k tbn, 180k tbc
Output #0, mp4, to 'outputfile1.mp4':
Metadata:
title : -
encoder : Lavf58.20.100
Stream #0:0: Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1920x1080, q=2-31, 25 tbr, 90k tbn, 90k tbc
Output #1, mp4, to 'outputfile2.mp4':
Metadata:
title : -
encoder : Lavf58.20.100
Stream #1:0: Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1920x1080, q=2-31, 25 tbr, 90k tbn, 90k tbc
Output #2, mp4, to 'outputfile3.mp4':
Metadata:
title : -
encoder : Lavf58.20.100
Stream #2:0: Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1920x1080, q=2-31, 25 tbr, 90k tbn, 90k tbc
Output #3, mp4, to 'outputfile4.mp4':
Metadata:
title : -
encoder : Lavf58.20.100
Stream #3:0: Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1920x1080, q=2-31, 25 tbr, 90k tbn, 90k tbc
Output #4, mp4, to 'outputfile5.mp4':
Metadata:
title : -
encoder : Lavf58.20.100
Stream #4:0: Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 1920x1080, q=2-31, 25 tbr, 90k tbn, 90k tbc
Stream mapping:
Stream #0:0 -> #0:0 (copy)
Stream #1:0 -> #1:0 (copy)
Stream #2:0 -> #2:0 (copy)
Stream #3:0 -> #3:0 (copy)
Stream #4:0 -> #4:0 (copy)
Press [q] to stop, [?] for help
[mp4 @ 000001f27dd0d8c0] Timestamps are unset in a packet for stream 0. This is deprecated and will stop working in the future. Fix your code to set the timestamps properly
[mp4 @ 000001f27dd09040] Timestamps are unset in a packet for stream 0. This is deprecated and will stop working in the future. Fix your code to set the timestamps properly
[mp4 @ 000001f27dd09040] pts has no value
[mp4 @ 000001f27dc054c0] Timestamps are unset in a packet for stream 0. This is deprecated and will stop working in the future. Fix your code to set the timestamps properly
[mp4 @ 000001f27dc054c0] pts has no value
[mp4 @ 000001f27ddf86c0] Timestamps are unset in a packet for stream 0. This is deprecated and will stop working in the future. Fix your code to set the timestamps properly
[mp4 @ 000001f27ddf86c0] pts has no value
[mp4 @ 000001f27c743b00] Timestamps are unset in a packet for stream 0. This is deprecated and will stop working in the future. Fix your code to set the timestamps properly
[mp4 @ 000001f27c743b00] pts has no value
[mp4 @ 000001f27dd0d8c0] Non-monotonous DTS in output stream 0:0; previous: 0, current: 0; changing to 1. This may result in incorrect timestamps in the output file.
[mp4 @ 000001f27dd09040] Non-monotonous DTS in output stream 1:0; previous: 0, current: 0; changing to 1. This may result in incorrect timestamps in the output file.
[mp4 @ 000001f27dc054c0] Non-monotonous DTS in output stream 2:0; previous: 0, current: 0; changing to 1. This may result in incorrect timestamps in the output file.
[mp4 @ 000001f27ddf86c0] Non-monotonous DTS in output stream 3:0; previous: 0, current: 0; changing to 1. This may result in incorrect timestamps in the output file.
[mp4 @ 000001f27c743b00] Non-monotonous DTS in output stream 4:0; previous: 0, current: 0; changing to 1. This may result in incorrect timestamps in the output file.
[mp4 @ 000001f27dd09040] Non-monotonous DTS in output stream 1:0; previous: 1, current: 0; changing to 2. This may result in incorrect timestamps in the output file.
[mp4 @ 000001f27dc054c0] Non-monotonous DTS in output stream 2:0; previous: 1, current: 0; changing to 2. This may result in incorrect timestamps in the output file.
[mp4 @ 000001f27ddf86c0] Non-monotonous DTS in output stream 3:0; previous: 1, current: 0; changing to 2. This may result in incorrect timestamps in the output file.
[mp4 @ 000001f27c743b00] Non-monotonous DTS in output stream 4:0; previous: 1, current: 0; changing to 2. This may result in incorrect timestamps in the output file.
[rtsp @ 000001f27d2db700] max delay reached. need to consume packet
[rtsp @ 000001f27d2db700] RTP: missed 1644 packets
[rtsp @ 000001f27c721f40] max delay reached. need to consume packet
[rtsp @ 000001f27c721f40] RTP: missed 2461 packets
[rtsp @ 000001f27cfe9200] max delay reached. need to consume packet
[rtsp @ 000001f27cfe9200] RTP: missed 733 packets
frame= 46 fps=0.8 q=-1.0 Lq=-1.0 q=-1.0 q=-1.0 q=-1.0 size= 1790kB time=00:00:59.99 bitrate= 244.4kbits/s speed=1.04x
video:119011kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
有人可以帮我优化ffmpeg命令吗？
答案 0 :(得分：0)
请为RTP数据包设置套接字缓冲区大小。
buffer_size =大小 设置UDP最大套接字缓冲区大小（以字节为单位）。这用于设置接收或发送缓冲区的大小，具体取决于套接字的用途。默认值为64KB。另请参见fifo_size。
增加数据包的缓冲时间。
-max_delay
从日志中显示出很多数据包丢失正在发生。
RTP：丢失了2461个数据包
还要在ffmpeg的单独过程中尝试每个通道。