使用 ffmpeg 和 xfade 过滤器合并多个视频文件

问题描述

我需要将多个视频文件(包含音频)合并为一个视频.我注意到最近发布并使用了 xfade，但我遇到了音频同步问题.

I need to merge multiple video files (with included audio) into a single video. I've noticed xfade has been recently released and used it but I am running into an audio sync issue.

所有视频的视频和音频都采用相同的格式/分辨率/声望和比特率/等.

All videos are in the same format / resolution / fame and bitrate / etc both for video and audio.

这是我使用 0.5 个淡入淡出过渡合并 5 个不同持续时间的视频的方法:

Here is what I am using to merge 5 videos of various durations with 0.5 crossfade transitions:

ffmpeg
-i v0.mp4
-i v1.mp4
-i v2.mp4
-i v3.mp4
-i v4.mp4
-filter_complex
"[0][1]xfade=transition=fade:duration=0.5:offset=3.5[V01];
 [V01][2]xfade=transition=fade:duration=0.5:offset=32.75[V02];
 [V02][3]xfade=transition=fade:duration=0.5:offset=67.75[V03];
 [V03][4]xfade=transition=fade:duration=0.5:offset=98.75[video];
 [0:a][1:a]acrossfade=d=0.5:c1=tri:c2=tri[A01];
 [A01][2:a]acrossfade=d=0.5:c1=tri:c2=tri[A02];
 [A02][3:a]acrossfade=d=0.5:c1=tri:c2=tri[A03];
 [A03][4:a]acrossfade=d=0.5:c1=tri:c2=tri[audio]"
-vsync 0 -map "[video]" -map "[audio]" out.mp4

上面的代码生成一个带音频的视频.第一段和第二段与音频对齐，但从第二个过渡开始，声音未对齐.

The code above generates a video with audio. The first and second segment is aligned with audio but starting with the second transition the sound is misaligned.

推荐答案

您的偏移量不正确.试试:

Your offsets are incorrect. Try:

ffmpeg -i v0.mp4 -i v1.mp4 -i v2.mp4 -i v3.mp4 -i v4.mp4 -filter_complex
"[0][1:v]xfade=transition=fade:duration=1:offset=3[vfade1];
 [vfade1][2:v]xfade=transition=fade:duration=1:offset=10[vfade2];
 [vfade2][3:v]xfade=transition=fade:duration=1:offset=21[vfade3];
 [vfade3][4:v]xfade=transition=fade:duration=1:offset=25,format=yuv420p;
 [0:a][1:a]acrossfade=d=1[afade1];
 [afade1][2:a]acrossfade=d=1[afade2];
 [afade2][3:a]acrossfade=d=1[afade3];
 [afade3][4:a]acrossfade=d=1"
-movflags +faststart out.mp4

如何获得 xfade offset 值:

How to get xfade offset values:

输入	输入时长	+	上一个xfade offset	-	xfade duration	偏移量 =
v0.mp4	4	+	0	-	1	3
v1.mp4	8	+	3	-	1	10
v2.mp4	12	+	10	-	1	21
v3.mp4	5	+	21	-	1	25

• 参见 xfade 和 acrossfade 过滤器文档了解更多信息.
• 请参阅 FFmpeg Wiki:xfade，了解过渡效果库和更多示例.
• 您可以使用ffprobe获取输入持续时间.

• See xfade and acrossfade filter documentation for more info.
• See FFmpeg Wiki: xfade for a gallery of transition effects and more examples.
• You can get input durations with ffprobe.

这篇关于使用 ffmpeg 和 xfade 过滤器合并多个视频文件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！