<p><code>aivx</code> is simply a specific tag for 4K H.264 streams. Surprising that VLC doesn't probe the stream.</p>

<p>Try with</p>

<pre><code>ffmpeg -i myfile.mov -c:a copy -c:v libx264 -preset slower -crf 20 -vtag avc1 myfilearchive.mov
</code></pre>

<p>In some cases, ffmpeg may fail to set the tag without warning. Add <code>-strict -2</code> if that's the case.</p>

CC BY-SA 3.0
2017-05-04T15:58:42.013Z
In my case I needed to add `-strict -2` as suggested.
Patrick Kenny
CC BY-SA 4.0
2023-01-01T12:41:48.237Z
In my case, -strict -2 (equivalent to -strict experimental) was sufficient; no other explicit tags were necessary.
Kieran Tully
CC BY-SA 3.0
2017-05-04T09:12:26.757Z
2017-05-04T09:12:26.757Z
Gyan
<p>you can attach <code>-pix_fmt yuv420p</code>to make it compatible with VLC and QuickTime</p>

CC BY-SA 4.0
2018-12-21T13:15:49.770Z
2018-12-21T13:15:49.770Z
Fahad Hasan Pathik
<p>I am using the following command to make h264 archives of video with ffmpeg:</p>

<pre><code>ffmpeg -i myfile.mov -c:a copy -c:v libx264 -preset slower -crf 20 myfilearchive.mov
</code></pre>

<p>To get 10-bit h264 support for capture with decklink, I switched my ffmpeg from a version I downloaded from ffmpeg.org to a version I built using the <a href="https://github.com/jb-alvarado/media-autobuild_suite" rel="nofollow noreferrer">media autobuild suite</a>.  Now, however, <strong>when I run the same command to make an archive video, the output can't be played in VLC.</strong></p>

<p>This is the error I get in VLC:</p>

<blockquote>
  <p>Codec not supported: VLC could not decode the format "aivx" (No
  description for this codec)</p>
</blockquote>

<p>This is the output (from MediaInfo) for an archive video made with the ffmpeg I downloaded from ffmpeg.org:</p>

<pre><code>Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High 4:2:2@L5.2
Format settings, CABAC                   : Yes
Format settings, ReFrames                : 8 frames
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 5 min 4 s
Bit rate                                 : 26.3 Mb/s
Width                                    : 3 840 pixels
Height                                   : 2 160 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 29.970 (30000/1001) FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:2
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.106
Stream size                              : 953 MiB (92%)
Writing library                          : x264 core 148 r2721 72d53ab
Encoding settings                        : cabac=1 / ref=8 / deblock=1:0:0 / analyse=0x3:0x133 / me=umh / subme=9 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=12 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=crf / mbtree=1 / crf=20.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
Language                                 : English
</code></pre>

<p>This is the output (from MediaInfo) for an archive video made with the ffmpeg I built locally:</p>

<pre><code>Video
ID                                       : 1
Format                                   : aivx
Codec ID                                 : aivx
Duration                                 : 4 min 30 s
Bit rate                                 : 27.2 Mb/s
Width                                    : 3 840 pixels
Height                                   : 2 160 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 29.970 (30000/1001) FPS
Bits/(Pixel*Frame)                       : 0.110
Stream size                              : 878 MiB (92%)
Language                                 : English
</code></pre>

<p>Can I get playback in VLC by changing the command used to encode the videos?  (I want to use h264, but it doesn't have to be 10-bit for the archive.)  Or should I just use one ffmpeg for capture (with 10-bit support), and another ffmpeg for archival output (in other words, use the ffmpeg.org binary ffmpeg to do my archives)? </p>

<ffmpeg><encoding>
ffmpeg h264: VLC could not decode the format "aivx"
Patrick Kenny
# ffmpeg h264: VLC could not decode the format "aivx"

(Asked by: username_0 on 2017-05-04)

I am using the following command to make h264 archives of video with ffmpeg:
ffmpeg -i myfile.mov -c:a copy -c:v libx264 -preset slower -crf 20 myfilearchive.mov

To get 10-bit h264 support for capture with decklink, I switched my ffmpeg from a version I downloaded from ffmpeg.org to a version I built using the media autobuild suite.  Now, however, when I run the same command to make an archive video, the output can't be played in VLC.
This is the error I get in VLC:

Codec not supported: VLC could not decode the format "aivx" (No
  description for this codec)

This is the output (from MediaInfo) for an archive video made with the ffmpeg I downloaded from ffmpeg.org:
Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High 4:2:2@L5.2
Format settings, CABAC                   : Yes
Format settings, ReFrames                : 8 frames
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 5 min 4 s
Bit rate                                 : 26.3 Mb/s
Width                                    : 3 840 pixels
Height                                   : 2 160 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 29.970 (30000/1001) FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:2
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.106
Stream size                              : 953 MiB (92%)
Writing library                          : x264 core 148 r2721 72d53ab
Encoding settings                        : cabac=1 / ref=8 / deblock=1:0:0 / analyse=0x3:0x133 / me=umh / subme=9 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=12 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=crf / mbtree=1 / crf=20.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
Language                                 : English

This is the output (from MediaInfo) for an archive video made with the ffmpeg I built locally:
Video
ID                                       : 1
Format                                   : aivx
Codec ID                                 : aivx
Duration                                 : 4 min 30 s
Bit rate                                 : 27.2 Mb/s
Width                                    : 3 840 pixels
Height                                   : 2 160 pixels
Display aspect ratio                     : 16:9
Frame rate mode                          : Constant
Frame rate                               : 29.970 (30000/1001) FPS
Bits/(Pixel*Frame)                       : 0.110
Stream size                              : 878 MiB (92%)
Language                                 : English

Can I get playback in VLC by changing the command used to encode the videos?  (I want to use h264, but it doesn't have to be 10-bit for the archive.)  Or should I just use one ffmpeg for capture (with 10-bit support), and another ffmpeg for archival output (in other words, use the ffmpeg.org binary ffmpeg to do my archives)?

**Tags:** ffmpeg, encoding


---

## 2 answers

### Answer by username_1 on 2017-05-04. Score: 2 | Accepted answer

aivx is simply a specific tag for 4K H.264 streams. Surprising that VLC doesn't probe the stream.
Try with
ffmpeg -i myfile.mov -c:a copy -c:v libx264 -preset slower -crf 20 -vtag avc1 myfilearchive.mov

In some cases, ffmpeg may fail to set the tag without warning. Add -strict -2 if that's the case.

> **Comments:**
> **username_0**: In my case I needed to add `-strict -2` as suggested.  
> **username_2**: In my case, -strict -2 (equivalent to -strict experimental) was sufficient; no other explicit tags were necessary.  

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### Answer by username_3 on 2018-12-21. Score: 1

you can attach `-pix_fmt yuv420p`to make it compatible with VLC and QuickTime


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