ffmpeg - 连接 2 个不同图像大小的多轨视频

Question

我尝试连接两个视频(1.mkv 的图像大小为 640:360，2.mkv 的图像大小为 1280:720)，两个视频都有 2 个视频轨道和 0 个音轨。我试过这段代码:

ffmpeg -i 1.mkv -i 2.mkv -filter_complex "[0:v:0]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:(ow-iw)/2:(oh-ih)/2[v0];[0:v:1]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:(ow-iw)/2:(oh-ih)/2[v0];[v0][1:v:0][1:v:1]concat=n=2:v=2:a=0[v]" -map "[v]" -c:v "libvpx" 1+2.mkv

但我错了:

Filter pad has an unconnected output

Answer 1

您的过滤器标签需要调整，您需要更改v=2至v=1在 concat 过滤器中:

ffmpeg -i 1.mkv -i 2.mkv -filter_complex "[0:v:0]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:(ow-iw)/2:(oh-ih)/2[v0];[1:v:0]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:(ow-iw)/2:(oh-ih)/2[v1];[v0][v1]concat=n=2:v=1:a=0[v]" -map "[v]" -c:v libvpx 1+2.mkv

由于 2.mkv已经是 1280x720 您可以避免处理该输入:

ffmpeg -i 1.mkv -i 2.mkv -filter_complex "[0:v:0]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:(ow-iw)/2:(oh-ih)/2[v0];[v0][1:v]concat=n=2:v=1:a=0[v]" -map "[v]" -c:v libvpx 1+2.mkv