Estou usando o ffmpeg de uma máquina debian na minha rede local. Esta máquina está escutando de fluxos recebidos:
$ ffmpeg -i udp://192.168.1.3:8080 /path/to/out.avi
E do meu macbook, enviando o vídeo em formato avi:
$ ffmpeg -f <input> -i "1" -f avi udp://192.168.1.3:8080
Os comandos acima funcionam, mas espero que alguns guru ffmpeg possam oferecer algumas dicas e truques de otimização para minimizar a carga da CPU no meu macbook, mantendo a qualidade de saída de vídeo.
Clique para ver a imagem
Algum argumento de otimização como bitrate (eu realmente não sei o que é isso), alternativas de formato de arquivo (algo melhor que avi?), resolução, protocolo (alternativas udp?) - qualquer coisa que possa manter o uso da CPU a um mínimo absoluto sem estragar completamente a qualidade da saída de vídeo.
Para uma pergunta clara:
Como posso minimizar o uso da CPU / MEM no macbook sem destruir a qualidade da saída de vídeo?
Aqui tentei usar o argumento -threads com -f mpegts , mas o uso da CPU ainda estava em torno de 45%.
$ cat ffmpeg-20180529-103103.log
ffmpeg started on 2018-05-29 at 10:31:03
Report written to "ffmpeg-20180529-103103.log"
Command line:
./ffmpeg -threads 1 -f avfoundation -i 1 -f mpegts -report udp://192.168.1.33:8080
ffmpeg version 4.0 Copyright (c) 2000-2018 the FFmpeg developers
built with Apple LLVM version 9.1.0 (clang-902.0.39.1)
configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib --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-appkit --enable-avfoundation --enable-coreimage --enable-audiotoolbox
libavutil 56. 14.100 / 56. 14.100
libavcodec 58. 18.100 / 58. 18.100
libavformat 58. 12.100 / 58. 12.100
libavdevice 58. 3.100 / 58. 3.100
libavfilter 7. 16.100 / 7. 16.100
libswscale 5. 1.100 / 5. 1.100
libswresample 3. 1.100 / 3. 1.100
libpostproc 55. 1.100 / 55. 1.100
Splitting the commandline.
Reading option '-threads' ... matched as AVOption 'threads' with argument '1'.
Reading option '-f' ... matched as option 'f' (force format) with argument 'avfoundation'.
Reading option '-i' ... matched as input url with argument '1'.
Reading option '-f' ... matched as option 'f' (force format) with argument 'mpegts'.
Reading option '-report' ... matched as option 'report' (generate a report) with argument '1'.
Reading option 'udp://192.168.1.33:8080' ... matched as output url.
Finished splitting the commandline.
Parsing a group of options: global .
Applying option report (generate a report) with argument 1.
Successfully parsed a group of options.
Parsing a group of options: input url 1.
Applying option f (force format) with argument avfoundation.
Successfully parsed a group of options.
Opening an input file: 1.
[avfoundation @ 0x7f9f56800000] '<AVCaptureScreenInput: 0x7f9f55532240>' opened
[avfoundation @ 0x7f9f56800000] Selected pixel format (yuv420p) is not supported by the input device.
[avfoundation @ 0x7f9f56800000] Supported pixel formats:
[avfoundation @ 0x7f9f56800000] uyvy422
[avfoundation @ 0x7f9f56800000] yuyv422
[avfoundation @ 0x7f9f56800000] nv12
[avfoundation @ 0x7f9f56800000] 0rgb
[avfoundation @ 0x7f9f56800000] bgr0
[avfoundation @ 0x7f9f56800000] Overriding selected pixel format to use uyvy422 instead.
[avfoundation @ 0x7f9f56800000] Probe buffer size limit of 5000000 bytes reached
[avfoundation @ 0x7f9f56800000] Stream #0: not enough frames to estimate rate; consider increasing probesize
Input #0, avfoundation, from '1':
Duration: N/A, start: 11870.909500, bitrate: N/A
Stream #0:0, 2, 1/1000000: Video: rawvideo (UYVY / 0x59565955), uyvy422, 1440x900, 1000k tbr, 1000k tbn, 1000k tbc
Successfully opened the file.
Parsing a group of options: output url udp://192.168.1.33:8080.
Applying option f (force format) with argument mpegts.
Successfully parsed a group of options.
Opening an output file: udp://192.168.1.33:8080.
[udp @ 0x7f9f55551c80] No default whitelist set
Successfully opened the file.
Stream mapping:
Stream #0:0 -> #0:0 (rawvideo (native) -> mpeg2video (native))
Press [q] to stop, [?] for help
cur_dts is invalid (this is harmless if it occurs once at the start per stream)
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
detected 4 logical cores
[graph 0 input from stream 0:0 @ 0x7f9f55551d00] Setting 'video_size' to value '1440x900'
[graph 0 input from stream 0:0 @ 0x7f9f55551d00] Setting 'pix_fmt' to value '15'
[graph 0 input from stream 0:0 @ 0x7f9f55551d00] Setting 'time_base' to value '1/1000000'
[graph 0 input from stream 0:0 @ 0x7f9f55551d00] Setting 'pixel_aspect' to value '0/1'
[graph 0 input from stream 0:0 @ 0x7f9f55551d00] Setting 'sws_param' to value 'flags=2'
[graph 0 input from stream 0:0 @ 0x7f9f55551d00] Setting 'frame_rate' to value '1000000/1'
[graph 0 input from stream 0:0 @ 0x7f9f55551d00] w:1440 h:900 pixfmt:uyvy422 tb:1/1000000 fr:1000000/1 sar:0/1 sws_param:flags=2
[format @ 0x7f9f555522c0] Setting 'pix_fmts' to value 'yuv420p|yuv422p'
[auto_scaler_0 @ 0x7f9f55552a80] Setting 'flags' to value 'bicubic'
[auto_scaler_0 @ 0x7f9f55552a80] w:iw h:ih flags:'bicubic' interl:0
[format @ 0x7f9f555522c0] auto-inserting filter 'auto_scaler_0' between the filter 'Parsed_null_0' and the filter 'format'
[AVFilterGraph @ 0x7f9f55729240] query_formats: 4 queried, 2 merged, 1 already done, 0 delayed
[auto_scaler_0 @ 0x7f9f55552a80] picking yuv422p out of 2 ref:uyvy422 alpha:0
[auto_scaler_0 @ 0x7f9f55552a80] w:1440 h:900 fmt:uyvy422 sar:0/1 -> w:1440 h:900 fmt:yuv422p sar:0/1 flags:0x4
[mpeg2video @ 0x7f9f56071a00] intra_quant_bias = 96 inter_quant_bias = 0
[mpegts @ 0x7f9f5606f600] muxrate VBR, pcr every 24 pkts, sdt every 200, pat/pmt every 40 pkts
Output #0, mpegts, to 'udp://192.168.1.33:8080':
Metadata:
encoder : Lavf58.12.100
Stream #0:0, 0, 1/90000: Video: mpeg2video (4:2:2), yuv422p, 1440x900, q=2-31, 200 kb/s, 240 fps, 90k tbn, 240 tbc
Metadata:
encoder : Lavc58.18.100 mpeg2video
Side data:
cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: -1
Clipping frame in rate conversion by 0.000008
cur_dts is invalid (this is harmless if it occurs once at the start per stream)
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918trate=8818.0kbits/s speed=1.01x
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918trate=5789.9kbits/s speed=0.996x
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
---[ a lot of these rawvideo lines; omitted for superuser ]---
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918trate=3320.8kbits/s speed=0.999x
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7f9f5606f000] PACKET SIZE: 2626592, STRIDE: 2918
frame= 744 fps= 30 q=31.0 Lsize= 9909kB time=00:00:24.73 bitrate=3282.0kbits/s speed=0.999x
video:9113kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 8.732401%
Input file #0 (1):
Input stream #0:0 (video): 744 packets read (1954184448 bytes); 744 frames decoded;
Total: 744 packets (1954184448 bytes) demuxed
Output file #0 (udp://192.168.1.33:8080):
Output stream #0:0 (video): 744 frames encoded; 744 packets muxed (9332015 bytes);
Total: 744 packets (9332015 bytes) muxed
744 frames successfully decoded, 0 decoding errors
[AVIOContext @ 0x7f9f5543ef80] Statistics: 0 seeks, 7244 writeouts
Usando novamente o formato -f avi e removendo o argumento -threads arg, o uso da CPU ainda não foi afetado em 45%.
$ cat ffmpeg-20180529-105147.log
ffmpeg started on 2018-05-29 at 10:51:47
Report written to "ffmpeg-20180529-105147.log"
Command line:
./ffmpeg -f avfoundation -i 1 -f avi -report udp://192.168.1.33:8080
ffmpeg version 4.0 Copyright (c) 2000-2018 the FFmpeg developers
built with Apple LLVM version 9.1.0 (clang-902.0.39.1)
configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib --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-appkit --enable-avfoundation --enable-coreimage --enable-audiotoolbox
libavutil 56. 14.100 / 56. 14.100
libavcodec 58. 18.100 / 58. 18.100
libavformat 58. 12.100 / 58. 12.100
libavdevice 58. 3.100 / 58. 3.100
libavfilter 7. 16.100 / 7. 16.100
libswscale 5. 1.100 / 5. 1.100
libswresample 3. 1.100 / 3. 1.100
libpostproc 55. 1.100 / 55. 1.100
Splitting the commandline.
Reading option '-f' ... matched as option 'f' (force format) with argument 'avfoundation'.
Reading option '-i' ... matched as input url with argument '1'.
Reading option '-f' ... matched as option 'f' (force format) with argument 'avi'.
Reading option '-report' ... matched as option 'report' (generate a report) with argument '1'.
Reading option 'udp://192.168.1.33:8080' ... matched as output url.
Finished splitting the commandline.
Parsing a group of options: global .
Applying option report (generate a report) with argument 1.
Successfully parsed a group of options.
Parsing a group of options: input url 1.
Applying option f (force format) with argument avfoundation.
Successfully parsed a group of options.
Opening an input file: 1.
[avfoundation @ 0x7fd46a80fe00] '<AVCaptureScreenInput: 0x7fd46a52e640>' opened
[avfoundation @ 0x7fd46a80fe00] Selected pixel format (yuv420p) is not supported by the input device.
[avfoundation @ 0x7fd46a80fe00] Supported pixel formats:
[avfoundation @ 0x7fd46a80fe00] uyvy422
[avfoundation @ 0x7fd46a80fe00] yuyv422
[avfoundation @ 0x7fd46a80fe00] nv12
[avfoundation @ 0x7fd46a80fe00] 0rgb
[avfoundation @ 0x7fd46a80fe00] bgr0
[avfoundation @ 0x7fd46a80fe00] Overriding selected pixel format to use uyvy422 instead.
[avfoundation @ 0x7fd46a80fe00] Probe buffer size limit of 5000000 bytes reached
[avfoundation @ 0x7fd46a80fe00] Stream #0: not enough frames to estimate rate; consider increasing probesize
Input #0, avfoundation, from '1':
Duration: N/A, start: 13115.322833, bitrate: N/A
Stream #0:0, 2, 1/1000000: Video: rawvideo (UYVY / 0x59565955), uyvy422, 1440x900, 1000k tbr, 1000k tbn, 1000k tbc
Successfully opened the file.
Parsing a group of options: output url udp://192.168.1.33:8080.
Applying option f (force format) with argument avi.
Successfully parsed a group of options.
Opening an output file: udp://192.168.1.33:8080.
[udp @ 0x7fd46a4319c0] No default whitelist set
Successfully opened the file.
Stream mapping:
Stream #0:0 -> #0:0 (rawvideo (native) -> mpeg4 (native))
Press [q] to stop, [?] for help
cur_dts is invalid (this is harmless if it occurs once at the start per stream)
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
detected 4 logical cores
[graph 0 input from stream 0:0 @ 0x7fd46a463080] Setting 'video_size' to value '1440x900'
[graph 0 input from stream 0:0 @ 0x7fd46a463080] Setting 'pix_fmt' to value '15'
[graph 0 input from stream 0:0 @ 0x7fd46a463080] Setting 'time_base' to value '1/1000000'
[graph 0 input from stream 0:0 @ 0x7fd46a463080] Setting 'pixel_aspect' to value '0/1'
[graph 0 input from stream 0:0 @ 0x7fd46a463080] Setting 'sws_param' to value 'flags=2'
[graph 0 input from stream 0:0 @ 0x7fd46a463080] Setting 'frame_rate' to value '1000000/1'
[graph 0 input from stream 0:0 @ 0x7fd46a463080] w:1440 h:900 pixfmt:uyvy422 tb:1/1000000 fr:1000000/1 sar:0/1 sws_param:flags=2
[format @ 0x7fd46a4645c0] Setting 'pix_fmts' to value 'yuv420p'
[auto_scaler_0 @ 0x7fd46a464c00] Setting 'flags' to value 'bicubic'
[auto_scaler_0 @ 0x7fd46a464c00] w:iw h:ih flags:'bicubic' interl:0
[format @ 0x7fd46a4645c0] auto-inserting filter 'auto_scaler_0' between the filter 'Parsed_null_0' and the filter 'format'
[AVFilterGraph @ 0x7fd46a42f2c0] query_formats: 4 queried, 2 merged, 1 already done, 0 delayed
[auto_scaler_0 @ 0x7fd46a464c00] w:1440 h:900 fmt:uyvy422 sar:0/1 -> w:1440 h:900 fmt:yuv420p sar:0/1 flags:0x4
[avi @ 0x7fd46b81aa00] Frame rate very high for a muxer not efficiently supporting it.
Please consider specifying a lower framerate, a different muxer or -vsync 2
[mpeg4 @ 0x7fd46b977200] intra_quant_bias = 0 inter_quant_bias = -64
[avi @ 0x7fd46b81aa00] reserve_index_space:0 master_index_max_size:256
[avi @ 0x7fd46b81aa00] duration_est:36000.000, filesize_est:0.9GiB, master_index_max_size:256
Output #0, avi, to 'udp://192.168.1.33:8080':
Metadata:
ISFT : Lavf58.12.100
Stream #0:0, 0, 1/600: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 1440x900, q=2-31, 200 kb/s, 65535 fps, 600 tbn, 65535 tbc
Metadata:
encoder : Lavc58.18.100 mpeg4
Side data:
cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: -1
Clipping frame in rate conversion by 0.000008
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918trate=6100.5kbits/s speed=1.16x
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
---[ a lot of these rawvideo lines; omitted for superuser ]---
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918trate=2806.4kbits/s speed=1.01x
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
[rawvideo @ 0x7fd46a840800] PACKET SIZE: 2626592, STRIDE: 2918
frame= 340 fps= 30 q=31.0 Lsize= 3879kB time=00:00:11.33 bitrate=2803.6kbits/s speed= 1x
video:3825kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 1.425499%
Input file #0 (1):
Input stream #0:0 (video): 340 packets read (893041280 bytes); 340 frames decoded;
Total: 340 packets (893041280 bytes) demuxed
Output file #0 (udp://192.168.1.33:8080):
Output stream #0:0 (video): 340 frames encoded; 340 packets muxed (3916524 bytes);
Total: 340 packets (3916524 bytes) muxed
340 frames successfully decoded, 0 decoding errors
[AVIOContext @ 0x7fd46a56ffc0] Statistics: 0 seeks, 2923 writeouts
Usar -s 1024x576 parece ajudar a reduzir o uso da CPU, mas o texto na saída de vídeo começa a ficar quase ilegível.