Answers.Body: <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>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-05-04T15:58:42.013Z
Answers.Text: In my case I needed to add `-strict -2` as suggested.
Answers.UserDisplayName: Patrick Kenny
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2023-01-01T12:41:48.237Z
Answers.Text: In my case, -strict -2 (equivalent to -strict experimental) was sufficient; no other explicit tags were necessary.
Answers.UserDisplayName: Kieran Tully
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-05-04T09:12:26.757Z
Answers.LastActivityDate: 2017-05-04T09:12:26.757Z
Answers.UserDisplayName: Gyan
Answers.Body: <p>you can attach <code>-pix_fmt yuv420p</code>to make it compatible with VLC and QuickTime</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2018-12-21T13:15:49.770Z
Answers.LastActivityDate: 2018-12-21T13:15:49.770Z
Answers.UserDisplayName: Fahad Hasan Pathik
Body: <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>
  
Tags: <ffmpeg><encoding>
Title: ffmpeg h264: VLC could not decode the format "aivx"
UserDisplayName: Patrick Kenny
ThreadText: # 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](https://github.com/jb-alvarado/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.  
  
  ---
  
  ### Answer by username_3 on 2018-12-21. Score: 1
  
  you can attach `-pix_fmt yuv420p`to make it compatible with VLC and QuickTime
  
  
  ---
  
  