FFmpeg 3.3.4 avfoundation 使用命令行在 macOS Sierra 上仅记录屏幕的特定部分
FFmpeg 3.3.4 avfoundation to record only a specific section of the screen on macOS Sierra using the command line
我正在通过命令行使用 FFmpeg 版本 3.3.4（通过 brew 安装）在我的 macOS Sierra (10.12.6) 上进行一些自动化测试时记录我的桌面。
我只想录制屏幕的特定部分，但不幸的是，我无法在文档中找到合适的选项来实现我的目标。
根据FFmpeg documentation for avfoundation，这是我使用的命令：
ffmpeg
-f avfoundation // avfoundation
-pix_fmt uyvy422 // pixel format
-i 1 // input: desktop
-r 30 // framerate for output
[PATH]/test.mp4 // filename
当我 运行 这个命令时，我有以下输出：
ffmpeg version 3.3.4 Copyright (c) 2000-2017 the FFmpeg developers
built with Apple LLVM version 9.0.0 (clang-900.0.37)
configuration: --prefix=/usr/local/Cellar/ffmpeg/3.3.4 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-gpl --enable-ffplay --enable-frei0r --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-libxvid --enable-opencl --enable-videotoolbox --enable-openssl --disable-lzma --enable-libopenjpeg --disable-decoder=jpeg2000 --extra-cflags=-I/usr/local/Cellar/openjpeg/2.3.0/include/openjpeg-2.3 --enable-nonfree --enable-vda
libavutil 55. 58.100 / 55. 58.100
libavcodec 57. 89.100 / 57. 89.100
libavformat 57. 71.100 / 57. 71.100
libavdevice 57. 6.100 / 57. 6.100
libavfilter 6. 82.100 / 6. 82.100
libavresample 3. 5. 0 / 3. 5. 0
libswscale 4. 6.100 / 4. 6.100
libswresample 2. 7.100 / 2. 7.100
libpostproc 54. 5.100 / 54. 5.100
[avfoundation @ 0x7fb7d4005800] Stream #0: not enough frames to estimate rate; consider increasing probesize
Input #0, avfoundation, from '1':
Duration: N/A, start: 7263.782833, bitrate: N/A
Stream #0:0: Video: rawvideo (UYVY / 0x59565955), uyvy422, 1920x1080, 1000k tbr, 1000k tbn, 1000k tbc
Stream mapping:
Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (libx264))
Press [q] to stop, [?] for help
No pixel format specified, yuv422p for H.264 encoding chosen.
Use -pix_fmt yuv420p for compatibility with outdated media players.
[libx264 @ 0x7fb7d4028400] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 AVX2 LZCNT BMI2
[libx264 @ 0x7fb7d4028400] profile High 4:2:2, level 4.0, 4:2:2 8-bit
[libx264 @ 0x7fb7d4028400] 264 - core 148 r2795 aaa9aa8 - H.264/MPEG-4 AVC codec - Copyleft 2003-2017 - 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=6 lookahead_threads=1 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 '[PATH]/test.mp4':
Metadata:
encoder : Lavf57.71.100
Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv422p, 1920x1080, q=-1--1, 30 fps, 15360 tbn, 30 tbc
Metadata:
encoder : Lavc57.89.100 libx264
Side data:
cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
frame= 83 fps= 28 q=-1.0 Lsize= 525kB time=00:00:02.66 bitrate=1612.6kbits/s dup=1 drop=0 speed=0.889x
我尝试使用 -video_size 选项来设置视频帧大小，但它不起作用。
首先你需要找到与你的屏幕对应的AVFoundation设备的名称：
ffmpeg -hide_banner -f avfoundation -list_devices true -i ""
[AVFoundation input device @ 0x7fc1cd40ec60] AVFoundation video devices:
[AVFoundation input device @ 0x7fc1cd40ec60] [0] HD Pro Webcam C920
[AVFoundation input device @ 0x7fc1cd40ec60] [1] FaceTime HD Camera (Built-in)
[AVFoundation input device @ 0x7fc1cd40ec60] [2] Capture screen 0
[AVFoundation input device @ 0x7fc1cd40ec60] AVFoundation audio devices:
[AVFoundation input device @ 0x7fc1cd40ec60] [0] HD Pro Webcam C920
[AVFoundation input device @ 0x7fc1cd40ec60] [1] Built-in Microphone
所以我的屏幕是设备 [2]，因为我连接了两个摄像头，它们是设备 [0] 和 [1]。
然后，由于您在 Mac，您可能希望使用 QuickTime 观看视频，因此您需要确保制作的视频兼容- 这意味着使用 -pix_fmt yuv420p.
ffmpeg -f avfoundation -i "2:0" -vf "crop=1024:768:400:800" -pix_fmt yuv420p -y -r 10 out.mov
1024x768 是视频的宽度和高度，400:800 是我要录制的屏幕左上角的偏移量。
我正在通过命令行使用 FFmpeg 版本 3.3.4（通过 brew 安装）在我的 macOS Sierra (10.12.6) 上进行一些自动化测试时记录我的桌面。
我只想录制屏幕的特定部分，但不幸的是，我无法在文档中找到合适的选项来实现我的目标。
根据FFmpeg documentation for avfoundation，这是我使用的命令：
ffmpeg
-f avfoundation // avfoundation
-pix_fmt uyvy422 // pixel format
-i 1 // input: desktop
-r 30 // framerate for output
[PATH]/test.mp4 // filename
当我 运行 这个命令时，我有以下输出：
ffmpeg version 3.3.4 Copyright (c) 2000-2017 the FFmpeg developers
built with Apple LLVM version 9.0.0 (clang-900.0.37)
configuration: --prefix=/usr/local/Cellar/ffmpeg/3.3.4 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-gpl --enable-ffplay --enable-frei0r --enable-libass --enable-libfdk-aac --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-libxvid --enable-opencl --enable-videotoolbox --enable-openssl --disable-lzma --enable-libopenjpeg --disable-decoder=jpeg2000 --extra-cflags=-I/usr/local/Cellar/openjpeg/2.3.0/include/openjpeg-2.3 --enable-nonfree --enable-vda
libavutil 55. 58.100 / 55. 58.100
libavcodec 57. 89.100 / 57. 89.100
libavformat 57. 71.100 / 57. 71.100
libavdevice 57. 6.100 / 57. 6.100
libavfilter 6. 82.100 / 6. 82.100
libavresample 3. 5. 0 / 3. 5. 0
libswscale 4. 6.100 / 4. 6.100
libswresample 2. 7.100 / 2. 7.100
libpostproc 54. 5.100 / 54. 5.100
[avfoundation @ 0x7fb7d4005800] Stream #0: not enough frames to estimate rate; consider increasing probesize
Input #0, avfoundation, from '1':
Duration: N/A, start: 7263.782833, bitrate: N/A
Stream #0:0: Video: rawvideo (UYVY / 0x59565955), uyvy422, 1920x1080, 1000k tbr, 1000k tbn, 1000k tbc
Stream mapping:
Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (libx264))
Press [q] to stop, [?] for help
No pixel format specified, yuv422p for H.264 encoding chosen.
Use -pix_fmt yuv420p for compatibility with outdated media players.
[libx264 @ 0x7fb7d4028400] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 AVX2 LZCNT BMI2
[libx264 @ 0x7fb7d4028400] profile High 4:2:2, level 4.0, 4:2:2 8-bit
[libx264 @ 0x7fb7d4028400] 264 - core 148 r2795 aaa9aa8 - H.264/MPEG-4 AVC codec - Copyleft 2003-2017 - 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=6 lookahead_threads=1 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 '[PATH]/test.mp4':
Metadata:
encoder : Lavf57.71.100
Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv422p, 1920x1080, q=-1--1, 30 fps, 15360 tbn, 30 tbc
Metadata:
encoder : Lavc57.89.100 libx264
Side data:
cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
frame= 83 fps= 28 q=-1.0 Lsize= 525kB time=00:00:02.66 bitrate=1612.6kbits/s dup=1 drop=0 speed=0.889x
我尝试使用 -video_size 选项来设置视频帧大小，但它不起作用。
首先你需要找到与你的屏幕对应的AVFoundation设备的名称：
ffmpeg -hide_banner -f avfoundation -list_devices true -i ""
[AVFoundation input device @ 0x7fc1cd40ec60] AVFoundation video devices:
[AVFoundation input device @ 0x7fc1cd40ec60] [0] HD Pro Webcam C920
[AVFoundation input device @ 0x7fc1cd40ec60] [1] FaceTime HD Camera (Built-in)
[AVFoundation input device @ 0x7fc1cd40ec60] [2] Capture screen 0
[AVFoundation input device @ 0x7fc1cd40ec60] AVFoundation audio devices:
[AVFoundation input device @ 0x7fc1cd40ec60] [0] HD Pro Webcam C920
[AVFoundation input device @ 0x7fc1cd40ec60] [1] Built-in Microphone
所以我的屏幕是设备 [2]，因为我连接了两个摄像头，它们是设备 [0] 和 [1]。
然后，由于您在 Mac，您可能希望使用 QuickTime 观看视频，因此您需要确保制作的视频兼容- 这意味着使用 -pix_fmt yuv420p.
ffmpeg -f avfoundation -i "2:0" -vf "crop=1024:768:400:800" -pix_fmt yuv420p -y -r 10 out.mov
1024x768 是视频的宽度和高度，400:800 是我要录制的屏幕左上角的偏移量。