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La grabación de ffmpeg se ralentiza cuando se agregan entradas de audio

tag-icon • tag-icon ffmpeg video-encoding recording
La grabación de ffmpeg se ralentiza cuando se agregan entradas de audio

Estoy intentando grabar mi pantalla, mi micrófono y el audio de mi juego con ffmpeg. Este comando registra solo mi pantalla.

ffmpeg \
-video_size 2560x1440 \
-framerate 60 \
-f x11grab -i :0 \
-map 0 \
-c:a copy \
-c:v libx264rgb \
-crf 0 \
-preset ultrafast \
video.mkv

Graba a una velocidad constante de 60 fps y ffmpeg proporciona la salida.

[x11grab @ 0x55717ef22dc0] Stream #0: not enough frames to estimate rate; consider increasing probesize
Input #0, x11grab, from ':0':
  Duration: N/A, start: 1635606965.195981, bitrate: N/A
    Stream #0:0: Video: rawvideo (BGR[0] / 0x524742), bgr0, 2560x1440, 60 fps, 1000k tbr, 1000k tbn, 1000k tbc
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (libx264rgb))
Press [q] to stop, [?] for help
[libx264rgb @ 0x55717ef30a40] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264rgb @ 0x55717ef30a40] profile High 4:4:4 Predictive, level 5.1, 4:4:4 8-bit
[libx264rgb @ 0x55717ef30a40] 264 - core 155 r2917 0a84d98 - H.264/MPEG-4 AVC codec - Copyleft 2003-2018 - http://www.videolan.org/x264.html - options: cabac=0 ref=1 deblock=0:0:0 analyse=0:0 me=dia subme=0 psy=0 mixed_ref=0 me_range=16 chroma_me=1 trellis=0 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=0 chroma_qp_offset=0 threads=18 lookahead_threads=3 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=250 keyint_min=25 scenecut=0 intra_refresh=0 rc=cqp mbtree=0 qp=0
Output #0, matroska, to 'video.mkv':
  Metadata:
    encoder         : Lavf58.29.100
    Stream #0:0: Video: h264 (libx264rgb) (H264 / 0x34363248), bgr0, 2560x1440, q=-1--1, 60 fps, 1k tbn, 60 tbc
    Metadata:
      encoder         : Lavc58.54.100 libx264rgb
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
frame=  174 fps= 60 q=-1.0 Lsize=    3866kB time=00:00:02.91 bitrate=10854.0kbits/s dup=0 drop=1 speed=1.01x

Si intento grabar mi audio agregando entradas al comando:

ffmpeg \
-video_size 2560x1440 \
-framerate 60 \
-f x11grab -i :0 \
-f pulse -i "alsa_output.usb-DeSheng_Electronics_Inc._XIBERIA-00.iec958-stereo.>
-f pulse -i "alsa_input.usb-DeSheng_Electronics_Inc._XIBERIA-00.mono-fallback" \
-map 0 -map 1 -map 2 \
-c:a copy \
-c:v libx264rgb \
-crf 0 \
-preset ultrafast \
video.mkv

ffmpeg da la salida

[x11grab @ 0x55bf9b4e80c0] Stream #0: not enough frames to estimate rate; consider increasing probesize
Input #0, x11grab, from ':0':
  Duration: N/A, start: 1635606747.731781, bitrate: N/A
    Stream #0:0: Video: rawvideo (BGR[0] / 0x524742), bgr0, 2560x1440, 60 fps, 1000k tbr, 1000k tbn, 1000k tbc
Guessed Channel Layout for Input Stream #1.0 : stereo
Input #1, pulse, from 'alsa_output.usb-DeSheng_Electronics_Inc._XIBERIA-00.iec958-stereo.monitor':
  Duration: N/A, start: 1635606747.770507, bitrate: 1536 kb/s
    Stream #1:0: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
Guessed Channel Layout for Input Stream #2.0 : stereo
Input #2, pulse, from 'alsa_input.usb-DeSheng_Electronics_Inc._XIBERIA-00.mono-fallback':
  Duration: N/A, start: 1635606747.811649, bitrate: 1536 kb/s
    Stream #2:0: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (libx264rgb))
  Stream #1:0 -> #0:1 (copy)
  Stream #2:0 -> #0:2 (copy)
Press [q] to stop, [?] for help
[libx264rgb @ 0x55bf9b519d80] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264rgb @ 0x55bf9b519d80] profile High 4:4:4 Predictive, level 5.1, 4:4:4 8-bit
[libx264rgb @ 0x55bf9b519d80] 264 - core 155 r2917 0a84d98 - H.264/MPEG-4 AVC codec - Copyleft 2003-2018 - http://www.videolan.org/x264.html - options: cabac=0 ref=1 deblock=0:0:0 analyse=0:0 me=dia subme=0 psy=0 mixed_ref=0 me_range=16 chroma_me=1 trellis=0 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=0 chroma_qp_offset=0 threads=18 lookahead_threads=3 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=250 keyint_min=25 scenecut=0 intra_refresh=0 rc=cqp mbtree=0 qp=0
Output #0, matroska, to 'video.mkv':
  Metadata:
    encoder         : Lavf58.29.100
    Stream #0:0: Video: h264 (libx264rgb) (H264 / 0x34363248), bgr0, 2560x1440, q=-1--1, 60 fps, 1k tbn, 60 tbc
    Metadata:
      encoder         : Lavc58.54.100 libx264rgb
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
    Stream #0:1: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz, stereo, s16, 1536 kb/s
    Stream #0:2: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz, stereo, s16, 1536 kb/s
[pulse @ 0x55bf9b4f4000] Thread message queue blocking; consider raising the thread_queue_size option (current value: 8)
[matroska @ 0x55bf9b518280] Non-monotonous DTS in output stream 0:1; previous: 364, current: 358; changing to 364. This may result in incorrect timestamps in the output file.
frame=   21 fps=0.0 q=0.0 size=       1kB time=00:00:01.01 bitrate=   7.7kbits/sframe=   21 fps= 21 q=0.0 size=       1kB time=00:00:01.01 bitrate=   7.7kbits/s
[matroska @ 0x55bf9b518280] Non-monotonous DTS in output stream 0:1; previous: 843, current: 838; changing to 843. This may result in incorrect timestamps in the output file.
[x11grab @ 0x55bf9b4e80c0] Thread message queue blocking; consider raising the thread_queue_size option (current value: 8)

y graba a 20 fps mientras imprime mensajes "DTS no monótonos" y "Bloqueo de cola de mensajes en hilo" cada pocos segundos. Supongo que el audio de alguna manera está ralentizando la grabación del vídeo, ¿cómo lo soluciono?

Respuesta1

Para cualquiera que tenga este problema en el futuro, lo solucioné abriendo pavucontrol durante la grabación.

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