【发布时间】：2020-06-03 02:09:31
【问题描述】：
我正在使用 ffmpeg 使用 xstack 过滤器创建视频马赛克。输入视频可能有不同的尺寸，所以我使用scale 过滤器预先缩放它们，我使用force_original_aspect_ratio 选项，然后使用pad 过滤器来保持每个视频的原始纵横比并在两侧添加黑条以使每个视频具有正确的尺寸。
我有一个有效的命令 - 但是，它不一致。对于某些维度，它有效，而对于其他维度则无效。
我正在使用 fluent-ffmpeg Node.js 模块从 Node.js 调用 ffmpeg。为此，我将一个字符串数组传递给complexFilter() 函数。
复杂过滤器的以下字符串有效：
"[0:v]scale=400:250:force_original_aspect_ratio=decrease,pad=400:250:(ow-iw)/2:(oh-ih)/2 [s0]"
"[1:v]scale=400:250:force_original_aspect_ratio=decrease,pad=400:250:(ow-iw)/2:(oh-ih)/2 [s1]"
"[s0][s1]xstack=inputs=2:fill='black':layout=0_0|w0_0[v]"
"[0:a][1:a]amix=inputs=2[a]"
但是，如果我将每个视频的输出尺寸更改为 400:225 而不是 400:250，则会失败。
"[0:v]scale=400:225:force_original_aspect_ratio=decrease,pad=400:225:(ow-iw)/2:(oh-ih)/2 [s0]"
"[1:v]scale=400:225:force_original_aspect_ratio=decrease,pad=400:225:(ow-iw)/2:(oh-ih)/2 [s1]"
"[s0][s1]xstack=inputs=2:fill='black':layout=0_0|w0_0[v]"
"[0:a][1:a]amix=inputs=2[a]"
给出以下错误：
An error occurred: ffmpeg exited with code 1: Error reinitializing filters!
Failed to inject frame into filter network: Invalid argument
Error while processing the decoded data for stream #1:1
Conversion failed!
如果相关，第一个视频的尺寸为 1280x720，而第二个视频的尺寸为 320x240。
有人知道为什么一组尺寸有效而另一组无效吗？
编辑：这是失败时的完整 ffmpeg 日志：
ffmpeg version git-2020-05-13-b12b053 Copyright (c) 2000-2020 the FFmpeg developers
built with gcc 9.3.1 (GCC) 20200513
configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libsrt --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --disable-w32threads --enable-libmfx --enable-ffnvcodec --enable-cuda-llvm --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt --enable-amf
libavutil 56. 45.100 / 56. 45.100
libavcodec 58. 84.100 / 58. 84.100
libavformat 58. 43.100 / 58. 43.100
libavdevice 58. 9.103 / 58. 9.103
libavfilter 7. 80.100 / 7. 80.100
libswscale 5. 6.101 / 5. 6.101
libswresample 3. 6.100 / 3. 6.100
libpostproc 55. 6.100 / 55. 6.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'C:/Users/user_name/Desktop/vids/vid1.mp4':
Metadata:
major_brand : mp42
minor_version : 0
compatible_brands: mp41isom
creation_time : 2020-05-21T15:52:20.000000Z
Duration: 00:00:10.76, start: 0.000000, bitrate: 8385 kb/s
Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuvj420p(pc), 1280x720 [SAR 1:1 DAR 16:9], 8237 kb/s, 29.99 fps, 30 tbr, 30k tbn, 60 tbc (default)
Metadata:
creation_time : 2020-05-21T15:52:20.000000Z
handler_name : VideoHandler
encoder : AVC Coding
Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 165 kb/s (default)
Metadata:
creation_time : 2020-05-21T15:52:20.000000Z
handler_name : SoundHandler
Input #1, mov,mp4,m4a,3gp,3g2,mj2, from 'C:/Users/user_name/Desktop/vids/vid2.mp4':
Metadata:
major_brand : mp42
minor_version : 0
compatible_brands: mp41isom
creation_time : 2020-05-21T15:54:37.000000Z
Duration: 00:00:11.01, start: 0.000000, bitrate: 836 kb/s
Stream #1:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuvj420p(pc), 320x240 [SAR 1:1 DAR 4:3], 669 kb/s, 29.88 fps, 30 tbr, 30k tbn, 60 tbc (default)
Metadata:
creation_time : 2020-05-21T15:54:37.000000Z
handler_name : VideoHandler
encoder : AVC Coding
Stream #1:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 163 kb/s (default)
Metadata:
creation_time : 2020-05-21T15:54:37.000000Z
handler_name : SoundHandler
Stream mapping:
Stream #0:0 (h264) -> scale
Stream #0:1 (aac) -> amix:input0
Stream #1:0 (h264) -> scale
Stream #1:1 (aac) -> amix:input1
xstack -> Stream #0:0 (libx264)
amix -> Stream #0:1 (aac)
Press [q] to stop, [?] for help
[swscaler @ 000001343fefc200] deprecated pixel format used, make sure you did set range correctly
[Parsed_pad_1 @ 000001343f8dc3c0] Padded dimensions cannot be smaller than input dimensions.
[Parsed_pad_1 @ 000001343f8dc3c0] Failed to configure input pad on Parsed_pad_1
Error reinitializing filters!
Failed to inject frame into filter network: Invalid argument
Error while processing the decoded data for stream #1:1
Conversion failed!
Done in 0.66s.
【问题讨论】：
-
分享完整的 ffmpeg 日志。
-
已编辑以包含完整的 ffmpeg 日志。
标签： node.js ffmpeg fluent-ffmpeg