python - FFMPEG - 为什么我不能录制超过 10 秒的视频？

Question

我正在使用 python 为 Windows 开发屏幕录像机，但由于某种原因，我无法录制超过 10 秒的视频。但是我可以录制超过 10 秒的音频。
我也在使用:

FFMPEG - 录制带有 mp4 扩展名的视频

PYAUDIO - 录制声音

TKINTER - 设计 GUI

由于问题出在视频录制上，因此我将保留与 ffmpeg 一起使用的代码:

"""
cmdGen.py generates ffmpeg commands to record your screen

"""
import os

class cmdGen:
    def __init__(self):
        self.fps = 60
        self.source = "desktop"
        self.encoder = 'mpeg4'
        self.hwaccel = None
        self.drawMouse = 1
        self.enableWebcam = False
        self.audList = 0
    def config(self,
                fps=None,source=None,encoder=None,
                hwaccel='unchanged',drawMouse=None,
                webcam=None,audList=None):
        if fps: self.fps = fps
        if source: self.source = source
        if encoder: self.encoder = encoder
        if hwaccel != 'unchanged': self.hwaccel = hwaccel
        if drawMouse: self.drawMouse = 0 if not self.drawMouse else 1
        if webcam: self.enableWebcam = bool(webcam)
        if audList: self.audList = audList
    def setSource(self,isWindow,windowName=""):
        if not isWindow:
            self.source = "desktop"
        else:
            self.source = "title="+windowName
    def setFps(self,fps):
        self.fps = fps
    def setEncode(self,encoder):
        self.encoder = encoder
    def getCmd(self,filename):
        print("ACK")
        finalCmd = ["ffmpeg.exe","-f","gdigrab"]
        finalCmd.extend(['-i',self.source])
        finalCmd.extend(['-framerate',str(self.fps)])
        finalCmd.extend(['-c:v',self.encoder])
        if self.encoder == 'mpeg4':
            finalCmd.extend(['-q:v','7'])
        if self.hwaccel: 
            finalCmd.extend(['-hwaccel',self.hwaccel])
        finalCmd.extend(['-draw_mouse',str(self.drawMouse)])
        finalCmd.extend(["-y", filename])
        print(finalCmd)
        return finalCmd
    def getCvtCmd(self,filename):
            # if self.rcchecked.get():
            #     self.mergeProcess = subprocess.Popen(args= ["ffmpeg","-i",'tmp/tmp.mkv','-i','tmp/tmp.wav','-i','tmp/webcamtmp.mkv','-filter_complex','[2:v] scale=640:-1 [inner]; [0:0][inner] overlay=0:0 [out]',"-shortest",'-map','[out]','-y',"ScreenCaptures/"+self.filename])
            # else:
            #     self.mergeProcess = subprocess.Popen(args= ["ffmpeg","-i",'tmp/tmp.mkv','-i','tmp/tmp.wav',"-shortest",'-y',"ScreenCaptures/"+self.filename], startupinfo=startupinfo)
        print("ACK")
        finalCmd = ["ffmpeg.exe"]
        finalCmd.extend(['-i','tmp/tmp.mkv'])
        for i in range(len(self.audList)):
            finalCmd.extend(['-i','tmp/tmp_'+str(i)+'.wav'])
        if len(self.audList) > 0:
            finalCmd.extend(['-filter_complex','amerge=inputs='+str(len(self.audList)),'-ac',str(len(self.audList))])
        # finalCmd.extend(['-c:v',self.encoder])
        if self.enableWebcam:
            finalCmd.extend(['-i','tmp/webcamtmp.mkv','-filter_complex','[2:v] scale=640:-1 [inner]; [0:0][inner] '
                                                                        'overlay=0:0 [out]','-map','[out]'])

        #finalCmd.extend(['-shortest'])
        finalCmd.extend(["-y", filename])
        print(finalCmd)
        return finalCmd

if __name__ == "__main__":
    cg = cmdGen()
    cg.setEncode("h264_nvenc")
    cg.setFps(60)
    cg.setSource(False)
    print(cg.getCmd("tmp"))

多谢你们

尝试记录 1 分钟的完整日志:

C:\Users\FabianoFreitas\AppData\Local\Programs\Python\Python37\python.exe C:/Users/FabianoFreitas/Desktop/PowerShare-v2.0/screenRecorder.py
ACK
['ffmpeg.exe', '-f', 'gdigrab', '-i', 'desktop', '-framerate', '60', '-c:v', 'mpeg4', '-q:v', '7', '-draw_mouse', '1', '-y', 'tmp/tmp.mkv']
* recording
ACK
['ffmpeg.exe', '-i', 'tmp/tmp.mkv', '-i', 'tmp/tmp_0.wav', '-filter_complex', 'amerge=inputs=1', '-ac', '1', '-y', 'Videos/ScreenCapture24.mp4']
* done recording
ffmpeg version git-2020-02-05-e6891d1 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 9.2.1 (GCC) 20200122
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --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-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt --enable-amf
  libavutil      56. 39.100 / 56. 39.100
  libavcodec     58. 67.101 / 58. 67.101
  libavformat    58. 37.100 / 58. 37.100
  libavdevice    58.  9.103 / 58.  9.103
  libavfilter     7. 74.100 /  7. 74.100
  libswscale      5.  6.100 /  5.  6.100
  libswresample   3.  6.100 /  3.  6.100
  libpostproc    55.  6.100 / 55.  6.100
Input #0, matroska,webm, from 'tmp/tmp.mkv':
  Metadata:
    ENCODER         : Lavf58.37.100
  Duration: N/A, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: mpeg4 (Simple Profile), yuv420p, 2560x1080 [SAR 1:1 DAR 64:27], 29.97 fps, 29.97 tbr, 1k tbn, 30k tbc (default)
    Metadata:
      ENCODER         : Lavc58.67.101 mpeg4
Guessed Channel Layout for Input Stream #1.0 : stereo
Input #1, wav, from 'tmp/tmp_0.wav':
  Duration: 00:01:09.08, bitrate: 1411 kb/s
    Stream #1:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, stereo, s16, 1411 kb/s
Stream mapping:
  Stream #1:0 (pcm_s16le) -> amerge (graph 0)
  amerge (graph 0) -> Stream #0:0 (aac)
  Stream #0:0 -> #0:1 (mpeg4 (native) -> h264 (libx264))
Press [q] to stop, [?] for help
[Parsed_amerge_0 @ 00000218cb4c1640] No channel layout for input 1
[libx264 @ 00000218cb4acdc0] using SAR=1/1
[libx264 @ 00000218cb4acdc0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 00000218cb4acdc0] profile High, level 5.0, 4:2:0, 8-bit
[libx264 @ 00000218cb4acdc0] 264 - core 159 - H.264/MPEG-4 AVC codec - Copyleft 2003-2019 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=12 lookahead_threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to 'Videos/ScreenCapture24.mp4':
  Metadata:
    encoder         : Lavf58.37.100
    Stream #0:0: Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 69 kb/s
    Metadata:
      encoder         : Lavc58.67.101 aac
    Stream #0:1: Video: h264 (libx264) (avc1 / 0x31637661), yuv420p, 2560x1080 [SAR 1:1 DAR 64:27], q=-1--1, 29.97 fps, 30k tbn, 29.97 tbc (default)
    Metadata:
      encoder         : Lavc58.67.101 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
[matroska,webm @ 00000218cb44af00] File ended prematurely
frame=  297 fps=113 q=-1.0 Lsize=    2325kB time=00:01:09.07 bitrate= 275.8kbits/s dup=22 drop=0 speed=26.2x    
video:1713kB audio:591kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.900237%
[aac @ 00000218cb4ab780] Qavg: 24995.135
[libx264 @ 00000218cb4acdc0] frame I:4     Avg QP:15.13  size:199596
[libx264 @ 00000218cb4acdc0] frame P:85    Avg QP:21.15  size:  9466
[libx264 @ 00000218cb4acdc0] frame B:208   Avg QP:24.93  size:   725
[libx264 @ 00000218cb4acdc0] consecutive B-frames:  5.1%  2.7%  6.1% 86.2%
[libx264 @ 00000218cb4acdc0] mb I  I16..4: 48.0% 45.3%  6.7%
[libx264 @ 00000218cb4acdc0] mb P  I16..4:  1.6%  1.9%  0.8%  P16..4:  1.4%  0.4%  0.3%  0.0%  0.0%    skip:93.7%
[libx264 @ 00000218cb4acdc0] mb B  I16..4:  0.1%  0.1%  0.0%  B16..8:  3.0%  0.1%  0.0%  direct: 0.0%  skip:96.6%  L0:51.2% L1:48.3% BI: 0.6%
[libx264 @ 00000218cb4acdc0] 8x8 transform intra:44.4% inter:69.1%
[libx264 @ 00000218cb4acdc0] coded y,uvDC,uvAC intra: 23.8% 27.4% 19.5% inter: 0.2% 0.3% 0.1%
[libx264 @ 00000218cb4acdc0] i16 v,h,dc,p: 54% 45%  1%  0%
[libx264 @ 00000218cb4acdc0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 26% 20% 41%  2%  2%  1%  2%  1%  5%
[libx264 @ 00000218cb4acdc0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 29% 35% 17%  2%  3%  3%  4%  2%  4%
[libx264 @ 00000218cb4acdc0] i8c dc,h,v,p: 61% 25% 11%  2%
[libx264 @ 00000218cb4acdc0] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 00000218cb4acdc0] ref P L0: 68.0%  6.3% 16.6%  9.1%
[libx264 @ 00000218cb4acdc0] ref B L0: 70.2% 23.7%  6.1%
[libx264 @ 00000218cb4acdc0] ref B L1: 91.1%  8.9%
[libx264 @ 00000218cb4acdc0] kb/s:1415.80

Answer 1

看起来您忘记了从 Python 代码执行命令。

要录制 50 秒，您可以使用以下代码:

cmd = cg.getCmd("tmp.mkv")
try:
    proc = subprocess.call(cmd, timeout=50)
except subprocess.TimeoutExpired:
    print('\n\nDone!')

我把它放在 print(cg.getCmd("tmp")) 之后，它正在记录 50 秒到 tmp.mkv .

评论:
它实际上只记录了 45 秒，我猜在缓冲区刷新到磁盘之前已处理完。

更新:

在 50 秒后终止进程并不是一个好主意。
添加 -t 50 FFmpeg 的参数用于记录 50 秒的命令行(并设置更大的超时时间)。