我正在尝试连接2个视频，同时在第二个视频中添加一些文本。我正在使用带有Sharapov扩展名的php-ffmpeg来执行此操作，但是我有实际的ffmpeg命令。
要执行此操作，似乎先对第一个视频进行编码，然后对第二个视频分别与文本进行编码，然后将它们合并在一起。问题在于文本出现在已编码（但未加入）的第二个视频中，但是一旦它们合并在一起，它就会消失。
以下是命令：
ffmpeg '-y' '-i' 'video_in/first_vid.mp4' '-threads' '8' '-vcodec' 'libx264' '-acodec' 'aac' '-max_muxing_queue_size' '400' '-b:v' '1000k' '-refs' '6' '-coder' '1' '-sc_threshold' '40' '-flags' '+loop' '-me_range' '16' '-subq' '7' '-i_qfactor' '0.71' '-qcomp' '0.6' '-qdiff' '4' '-trellis' '1' '-b:a' '256k' '-ac' '2' '-pass' '1' '-passlogfile' '/tmp/ffmpeg-passes5b73814fa1e29qjif7/pass-5b73814fa1f5b' '/data/tmp/ffmpeg-7a580007c010377da19305b0836e7a4d-5b73814f9ff35.mp4'
2% 2% 2% 4% 4% 6% 6% 6% 8% 8% 10% 10% 10% 12% 12% 12% 14% 14% 14% 16% 16% 18% 18% 18% 20% 20% 22% 22% 22% 24% 24% 24% 26% 26% 26% 28% 28% 28% 30% 30% 30% 32% 32% 34% 34% 34% 36% 36% 36% 38% 38% 38% 40% 40% 40% 42% 44% 44% 44% 46% 46% 46% 48% 48% 48%
ffmpeg '-y' '-i' 'video_in/first_vid.mp4' '-threads' '8' '-vcodec' 'libx264' '-acodec' 'aac' '-max_muxing_queue_size' '400' '-b:v' '1000k' '-refs' '6' '-coder' '1' '-sc_threshold' '40' '-flags' '+loop' '-me_range' '16' '-subq' '7' '-i_qfactor' '0.71' '-qcomp' '0.6' '-qdiff' '4' '-trellis' '1' '-b:a' '256k' '-ac' '2' '-pass' '2' '-passlogfile' '/tmp/ffmpeg-passes5b73814fa1e29qjif7/pass-5b73814fa1f5b' '/data/tmp/ffmpeg-7a580007c010377da19305b0836e7a4d-5b73814f9ff35.mp4'
50% 50% 50% 52% 52% 52% 52% 52% 52% 54% 54% 54% 54% 54% 54% 56% 56% 56% 56% 56% 56% 58% 58% 58% 58% 58% 58% 60% 60% 60% 60% 60% 60% 62% 62% 62% 62% 62% 62% 64% 64% 64% 64% 64% 66% 66% 66% 66% 66% 66% 66% 68% 68% 68% 68% 68% 70% 70% 70% 70% 70% 72% 72% 72% 72% 72% 72% 72% 74% 74% 74% 74% 74% 74% 74% 76% 76% 76% 76% 76% 76% 76% 78% 78% 78% 78% 78% 78% 80% 80% 80% 80% 80% 80% 82% 82% 82% 82% 82% 84% 84% 84% 84% 84% 84% 84% 84% 84% 84% 86% 86% 86% 86% 86% 86% 88% 88% 88% 88% 88% 88% 88% 90% 90% 90% 90% 90% 90% 90% 90% 92% 92% 92% 92% 94% 94% 94% 94% 94% 94% 94% 94% 94% 96% 96% 96% 96% 96% 96% 96% 96% 98% 98% 98% 98% 98% 98%
ffmpeg '-y' '-i' 'video/second_vid.mp4' '-filter_complex' '[0:v]drawtext=fontfile=/usr/share/fonts/truetype/msttcorefonts/arial.ttf:text='test text':fontcolor='ffffff@1':fontsize=30:x=(w-tw)/2:y=50:alpha='if(lt(t,2),0,if(lt(t,4),(t-2)/2,if(lt(t,24),1,if(lt(t,26),(2-(t-24))/2,0))))'' '-threads' '8' '-vcodec' 'libx264' '-acodec' 'aac' '-max_muxing_queue_size' '400' '-b:v' '1000k' '-refs' '6' '-coder' '1' '-sc_threshold' '40' '-flags' '+loop' '-me_range' '16' '-subq' '7' '-i_qfactor' '0.71' '-qcomp' '0.6' '-qdiff' '4' '-trellis' '1' '-b:a' '256k' '-ac' '2' '-pass' '1' '-passlogfile' '/tmp/ffmpeg-passes5b738244e22e0b38pp/pass-5b738244e2412' '/data/tmp/ffmpeg-ed6a389106090a6a9f9c71c7c357400b-5b738244e2215.mp4'
2% 2% 4% 6% 8% 10% 12% 14% 14% 16% 18% 18% 20% 22% 22% 24% 26% 28% 30% 30% 32% 34% 34% 36% 38% 40% 42% 44% 44% 46% 48%
ffmpeg '-y' '-i' 'video/second_vid.mp4' '-filter_complex' '[0:v]drawtext=fontfile=/usr/share/fonts/truetype/msttcorefonts/arial.ttf:text='test text':fontcolor='ffffff@1':fontsize=30:x=(w-tw)/2:y=50:alpha='if(lt(t,2),0,if(lt(t,4),(t-2)/2,if(lt(t,24),1,if(lt(t,26),(2-(t-24))/2,0))))'' '-threads' '8' '-vcodec' 'libx264' '-acodec' 'aac' '-max_muxing_queue_size' '400' '-b:v' '1000k' '-refs' '6' '-coder' '1' '-sc_threshold' '40' '-flags' '+loop' '-me_range' '16' '-subq' '7' '-i_qfactor' '0.71' '-qcomp' '0.6' '-qdiff' '4' '-trellis' '1' '-b:a' '256k' '-ac' '2' '-pass' '2' '-passlogfile' '/tmp/ffmpeg-passes5b738244e22e0b38pp/pass-5b738244e2412' '/data/tmp/ffmpeg-ed6a389106090a6a9f9c71c7c357400b-5b738244e2215.mp4'
52% 52% 54% 54% 56% 56% 58% 58% 60% 60% 62% 64% 66% 68% 70% 70% 72% 74% 76% 76% 78% 80% 82% 84% 86% 86% 88% 88% 90% 90% 92% 94% 96% 98%
ffmpeg '-y' '-f' 'concat' '-safe' '0' '-i' '/data/tmp/ffmpeg-concat-5b73814f9fe10' '-c' 'copy' 'video_out/done_vid.mp4'
（由于某种原因，似乎再次以50％的频率运行每个视频命令的编码）
因此，当我播放ffmpeg-ed6a389106090a6a9f9c71c7c357400b-5b738244e2215.mp4时，文本在那里，但是当我播放输出文件（done_vid.mp4）时，文本不在那里。
这是怎么回事？
更新：以下是这两个临时文件的ffprobes，以防它们起作用：
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'data/tmp/ffmpeg-7a580007c010377da19305b0836e7a4d-5b73814f9ff35.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf57.83.100
Duration: 00:02:25.17, start: 0.000000, bitrate: 1247 kb/s
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 999 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 47.95 tbc (default)
Metadata:
handler_name : VideoHandler
Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 242 kb/s (default)
Metadata:
handler_name : SoundHandler
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'data/tmp/ffmpeg-ed6a389106090a6a9f9c71c7c357400b-5b738244e2215.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf57.83.100
Duration: 00:01:30.03, start: 0.000000, bitrate: 322 kb/s
Stream #0:0(und): Video: h264 (High 4:4:4 Predictive) (avc1 / 0x31637661), yuv444p, 1280x720 [SAR 1:1 DAR 16:9], 61 kb/s, 23.98 fps, 23.98 tbr, 19184 tbn, 47.96 tbc (default)
Metadata:
handler_name : VideoHandler
Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 258 kb/s (default)
Metadata:
handler_name : SoundHandler
答案 0 :(得分：0)
您的第一个视频输出是yuv420p，但是您的第二个视频输出是yuv444p。两者都应为yuv420p，因此请将format=yuv420p添加到过滤链的末尾：
'-filter_complex' '[0:v]drawtext=fontfile=/usr/share/fonts/truetype/msttcorefonts/arial.ttf:text='test text':fontcolor='ffffff@1':fontsize=30:x=(w-tw)/2:y=50:alpha='if(lt(t,2),0,if(lt(t,4),(t-2)/2,if(lt(t,24),1,if(lt(t,26),(2-(t-24))/2,0))))',format=yuv420p'
-crf而不是-b:v使用一次。参见FFmpeg Wiki: H.264。-threads。编码器将自动选择合适的值。'-refs' '6' '-coder' '1' '-sc_threshold' '40' '-flags' '+loop' '-me_range' '16' '-subq' '7' '-i_qfactor' '0.71' '-qcomp' '0.6' '-qdiff' '4' '-trellis' '1'。-movflags +faststart输出选项，以便它可以在播放器完全下载之前开始播放。