Answers.Body: <p>There could be many reasons, for example: that device can have very low level hardware decoder or low quality USB port (especially if the device does not come from some widely known and good brand). The first thing I would try is to use the Base codec profile instead of the Main one, the second thing is to downscale the resolution.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-02-16T18:51:34.887Z
Answers.LastActivityDate: 2022-02-17T12:38:33.297Z
Answers.LastEditDate: 2022-02-17T12:38:33.297Z
Answers.UserDisplayName: Lex
Body: <p>I have a very specific goal: there is a device which is advertised to be able to playback my own media files from USB-pendrive, and I'm intended to do so.</p>
  <p>Further details are not disclosed about supported codecs, containers, fps, etc, so I did the easiest way first and tried with a <code>h264</code> video in <code>MP4</code> container:</p>
  <pre><code>Format                                   : MPEG-4
  Format profile                           : Base Media / Version 2
  Codec identifier                         : mp42 (isom/mp42)
  File size                                : 23,0 MiB
  Duration                                 : 6 perc 22 mp
  Bitrate                                  : VBR 505 kb/s
  gsst                                     : 0
  gstd                                     : 382688
  
  Image
  Streams                                  : 1
  Format                                   : AVC
  Format profile                           : Main@L3.1
  Format settings                          : CABAC / 3 Ref Frames
  Codec identifier                         : avc1
  Duration                                 : 6 min 22 sec
  Bitrate                                  : 373 kb/s
  Width                                    : 1280 px
  Height                                   : 720 px
  Ratio                                    : 16:9
  Frame per second                         : fixed, 23,976 (24000/1001) FPS
  Color space                              : YUV
  Chroma subsampling                       : 4:2:0
  Bit depth                                : 8 bit
  Data size                                : 17,0 MiB (74%)
  Color range                              : Limited
  Color primaries                          : BT.709
  Transfer characteristics                 : BT.709
  Matrix coefficients                      : BT.709
  Codec configuration box                  : avcC
  
  Sound
  Streams                                  : 2
  Format                                   : AAC LC
  Codec identifier                         : mp4a-40-2
  Duration                                 : 6 perc 22 mp
  Bitrate                                  : VBR, 128 kb/s
  Channels                                 : 2
  Channel layout                           : L R
  Sampling rate                            : 44,1 kHz
  Frame per second                         : 43,066 FPS (1024 SPF)
  Compression mode                         : Lossy
  Data size                                : 5,84 MiB (25%)
  Language                                 : English
  </code></pre>
  <p>Video playback started, but it was choppy, here is a sample (audio is also chopping, in-sync with video):</p>
  <p><a href="https://i.sstatic.net/UWgnb.gif" rel="nofollow noreferrer"><img src="https://i.sstatic.net/UWgnb.gif" alt="enter image description here" /></a></p>
  <p>This is an in-flight entertainment, so I don't really have too much trials, and I have to prepare before getting onto the plane.</p>
  <p>What could be the reason this video is that choppy, and what would you recommend me to try?
  Resolution seems reasonable, bitrate is not high, duration not too much, codec is a well-known one.</p>
  <p>I would be interested in which parameters might worth changing. I'd put various versions onto a thumbdrive, and give them a test.</p>
  
Tags: <encoding>
Title: Possible reasons of choppy video
UserDisplayName: Daniel
ThreadText: # Possible reasons of choppy video
  
  (Asked by: username_0 on 2022-02-13)
  
  I have a very specific goal: there is a device which is advertised to be able to playback my own media files from USB-pendrive, and I'm intended to do so.
  
  Further details are not disclosed about supported codecs, containers, fps, etc, so I did the easiest way first and tried with a `h264` video in `MP4` container:
  
  ```
  Format                                   : MPEG-4
  Format profile                           : Base Media / Version 2
  Codec identifier                         : mp42 (isom/mp42)
  File size                                : 23,0 MiB
  Duration                                 : 6 perc 22 mp
  Bitrate                                  : VBR 505 kb/s
  gsst                                     : 0
  gstd                                     : 382688
  
  Image
  Streams                                  : 1
  Format                                   : AVC
  Format profile                           : Main@L3.1
  Format settings                          : CABAC / 3 Ref Frames
  Codec identifier                         : avc1
  Duration                                 : 6 min 22 sec
  Bitrate                                  : 373 kb/s
  Width                                    : 1280 px
  Height                                   : 720 px
  Ratio                                    : 16:9
  Frame per second                         : fixed, 23,976 (24000/1001) FPS
  Color space                              : YUV
  Chroma subsampling                       : 4:2:0
  Bit depth                                : 8 bit
  Data size                                : 17,0 MiB (74%)
  Color range                              : Limited
  Color primaries                          : BT.709
  Transfer characteristics                 : BT.709
  Matrix coefficients                      : BT.709
  Codec configuration box                  : avcC
  
  Sound
  Streams                                  : 2
  Format                                   : AAC LC
  Codec identifier                         : mp4a-40-2
  Duration                                 : 6 perc 22 mp
  Bitrate                                  : VBR, 128 kb/s
  Channels                                 : 2
  Channel layout                           : L R
  Sampling rate                            : 44,1 kHz
  Frame per second                         : 43,066 FPS (1024 SPF)
  Compression mode                         : Lossy
  Data size                                : 5,84 MiB (25%)
  Language                                 : English
  
  ```
  
  Video playback started, but it was choppy, here is a sample (audio is also chopping, in-sync with video):
  
  [![enter image description here](https://i.sstatic.net/UWgnb.gif)](https://i.sstatic.net/UWgnb.gif)
  
  This is an in-flight entertainment, so I don't really have too much trials, and I have to prepare before getting onto the plane.
  
  What could be the reason this video is that choppy, and what would you recommend me to try?
  Resolution seems reasonable, bitrate is not high, duration not too much, codec is a well-known one.
  
  I would be interested in which parameters might worth changing. I'd put various versions onto a thumbdrive, and give them a test.
  
  **Tags:** encoding
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2022-02-16. Score: 2
  
  There could be many reasons, for example: that device can have very low level hardware decoder or low quality USB port (especially if the device does not come from some widely known and good brand). The first thing I would try is to use the Base codec profile instead of the Main one, the second thing is to downscale the resolution.
  
  
  ---
  
  