如何在不同属性的ffmpeg中串接视频？

Question

我试图合并一些视频，但我得到时间戳错误。

我试图让它们都相等，具有相同的尺寸，帧率，采样率，还通过添加一个音频轨道，当没有。

ffmpeg -i input1.mp4 -y -i audio1.mp3 -c:v copy -c:a aac -shortest output1.mp4
ffmpeg -i input2.mp4 -y -i audio2.mp3 -c:v copy -c:a aac -shortest output2.mp4
ffmpeg -y -safe 0 -f concat -i list.txt -c copy output.mp4

错误消息：

Non-monotonous DTS in output stream 0:0; previous: 8052684, current: 4127401; changing to 8052685. This may result in incorrect timestamps in the output file.

Answer 1

使用scale（宽度x高度/分辨率）、setsar（纵横比）、fps（帧率）、format（色度子采样）和concat（串联/连接）过滤器。

ffmpeg -i 1.mp4 -i 2.mp4 -i 3.mp4 -filter_complex \
"[0:v]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:-1:-1,setsar=1,fps=30,format=yuv420p[v0];
 [1:v]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:-1:-1,setsar=1,fps=30,format=yuv420p[v1];
 [2:v]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:-1:-1,setsar=1,fps=30,format=yuv420p[v2];
 [v0][0:a][v1][1:a][v2][2:a]concat=n=3:v=1:a=1[v][a]" \
-map "[v]" -map "[a]" -c:v libx264 -c:a aac -movflags +faststart output.mp4

增加了aformat（采样率和通道布局）过滤器。

ffmpeg -i 1.mp4 -i 2.mp4 -i 3.mp4 -filter_complex \
"[0:v]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:-1:-1,setsar=1,fps=30,format=yuv420p[v0];
 [1:v]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:-1:-1,setsar=1,fps=30,format=yuv420p[v1];
 [2:v]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:-1:-1,setsar=1,fps=30,format=yuv420p[v2];
 [0:a]aformat=sample_rates=48000:channel_layouts=stereo[a0];
 [1:a]aformat=sample_rates=48000:channel_layouts=stereo[a1];
 [2:a]aformat=sample_rates=48000:channel_layouts=stereo[a2];
 [v0][a0][v1][a1][v2][a2]concat=n=3:v=1:a=1[v][a]" \
-map "[v]" -map "[a]" -c:v libx264 -c:a aac -movflags +faststart output.mp4

ffmpeg -i 1.mp4 -i 2.mp4 -i 3.mp4 -i logo.png -filter_complex \
"[0:v]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:-1:-1,setsar=1,fps=30,format=yuv420p[v0];
 [1:v]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:-1:-1,setsar=1,fps=30,format=yuv420p[v1];
 [2:v]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:-1:-1,setsar=1,fps=30,format=yuv420p[v2];
 [0:a]aformat=sample_rates=48000:channel_layouts=stereo[a0];
 [1:a]aformat=sample_rates=48000:channel_layouts=stereo[a1];
 [2:a]aformat=sample_rates=48000:channel_layouts=stereo[a2];
 [v0][a0][v1][a1][v2][a2]concat=n=3:v=1:a=1[vid][a];[vid][3]overlay=W-w-5:H-h-5[v]" \
-map "[v]" -map "[a]" -c:v libx264 -c:a aac -movflags +faststart output.mp4

有关更多信息，请参见覆盖过滤器文档以及如何使用FFMPEG添加和定位水印？

ffmpeg -i 1.mp4 -i 2.mp4 -i 3.mp4 -t 0.1 -f lavfi -i anullsrc=channel_layout=stereo:sample_rate=48000 -filter_complex \
"[0:v]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:-1:-1,setsar=1,fps=30,format=yuv420p[v0];
 [1:v]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:-1:-1,setsar=1,fps=30,format=yuv420p[v1];
 [2:v]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720::-1:-1,setsar=1,fps=30,format=yuv420p[v2];
 [0:a]aformat=sample_rates=48000:channel_layouts=stereo[a0];
 [2:a]aformat=sample_rates=48000:channel_layouts=stereo[a2];
 [v0][a0][v1][3:a][v2][a2]concat=n=3:v=1:a=1[v][a]" \
-map "[v]" -map "[a]" -c:v libx264 -c:a aac -movflags +faststart output.mp4

注意：保持-t0.1不变：anullsrc的持续时间只需短于相关视频输入的持续时间。concat过滤器将自动扩展静音音频以匹配关联视频输入的长度。