使用ffmpeg和xfade过滤器合并多个视频文件 [英] Merging multiple video files with ffmpeg and xfade filter

问题描述

我需要将多个视频文件(包含音频)合并到一个视频中.我注意到xfade最近已经发布并使用过，但是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.

所有视频的音频和视频格式/分辨率/成名率和比特率均相同.

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

这是我用来合并5个具有0.5淡入淡出过渡的不同时长的视频的方法:

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

上面的代码生成带音频的视频.第一部分和第二部分与音频对齐，但是从第二个过渡开始，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]xfade=transition=fade:duration=0.5:offset=3.5[V01]; \
 [V01][2]xfade=transition=fade:duration=0.5:offset=12.1[V02]; \
 [V02][3]xfade=transition=fade:duration=0.5:offset=15.1[V03]; \
 [V03][4]xfade=transition=fade:duration=0.5:offset=22.59,format=yuv420p[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]" \
-map "[video]" -map "[audio]" -movflags +faststart out.mp4

如何获取xfade offset 值:

How to get xfade offset values:

<身体>

输入	输入持续时间	+	上一个xfade offset	-	xfade duration	=
v0.mp4	4.00	+	0	-	0.5	3.5
v1.mp4	9.19	+	3.5	-	0.5	12.1
v2.mp4	3.41	+	12.1	-	0.5	15.1
v3.mp4	7.99	+	15.1	-	0.5	22.59

input	input duration	+	previous xfade offset	-	xfade duration	=
v0.mp4	4.00	+	0	-	0.5	3.5
v1.mp4	9.19	+	3.5	-	0.5	12.1
v2.mp4	3.41	+	12.1	-	0.5	15.1
v3.mp4	7.99	+	15.1	-	0.5	22.59

• 请参见 xfade 和使用 ffprobe 获取输入持续时间.
• See xfade and acrossfade filter documentation for more info.
• You can get input durations with ffprobe.

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