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• Android Exoplayer garbled mp4 video output on imagereader surface while playing fine on SurfaceView (Samsung galaxy tab s7)

  29 mars 2023, par Orcun

  Problem :

  


  I am trying to play an mp4 video file on Samsung Galaxy Tab S7 for video processing purposes. For the purpose, I use Exoplayer(v2.18.4) library to be able to play the video onto an ImageReader surface so that I can grab the frames in ImageReader.OnImageAvailableListener.

  


  I do not have any problems in getting the frames. However, the frames I acquire are garbled/corrupted like :

  


  

  


  When I saw this frame, it made me think that it is some sort of color format or codec issue for the mp4 file or device I use. In logcat, there are no errors reported.
Device uses [OMX.qcom.video.decoder.avc] decoder. Also, same video plays nicely on some other devices that use exactly the same decoder.

  


  What I tried so far :

  


  I tried a lot of things to understand the root cause and also find a solution, so my brain currently is free flowing stream. I will try to summarise, please bear with me.

  


  I use a CustomMediaCodecVideoRenderer in my app which overrides MediaCodecVideoRenderer.getMediaFormat of Exoplayer to set color format like :

  


  setInteger(MediaFormat.KEY_COLOR_FORMAT, MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420Flexible)


  


  This step proved itself necessary. Without it I get a crash simply because I cannot access the image planes of an image frame in expected YUV image format.
This unfortunately was not enough for the Samsung Galaxy Tab 7 although it was already enough for another device like Xiaomi to render the image correctly.

  


  Then I decided to use a library like ffmpeg to modify the mp4 file itself to maybe use a different profile, color format, resolution that is widely compatible in android devices. No luck so far.
a quick ffprobe on my mp4 file shows :

  


  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'outputyuv169.mp4':
Metadata:
  major_brand     : isom
  minor_version   : 512
  compatible_brands: isomiso2avc1mp41
  encoder         : Lavf59.16.100
Duration: 00:03:00.02, start: 0.000000, bitrate: 4823 kb/s
Stream #0:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(progressive), 
1280x720 [SAR 1:1 DAR 16:9], 4820 kb/s, 30 fps, 30 tbr, 360k tbn (default)


  


  I tried even recording a simple video on the tablet itself and using that as my input file. Nevertheless, still getting similarly garbled frames.

  


  One thing I keep noticing in logcat is this line :

  


  [OMX.qcom.video.decoder.avc] using color format 0x7fa30c04 in place of 0x7f420888

  


  and

  


  [OMX.qcom.video.decoder.avc] Requested output format 0x7f420888 and got 0x7fa30c04

  


  where 0x7fa30c04 refers to YCbCr_420_SP_VENUS_UBWC. Not really sure If this has anything to do with it. I did not dive too deep into that because same log is present also on other device that renders the mp4 correctly.

  


  I would be grateful for any clue.

  


• FFmpeg export codec not supported by Samsung

  21 juillet 2021, par Coski

  I am using FFmpeg to render videos (concatenating image files with audio and then applying speed and volume filters) to export videos to upload to TikTok. As a result, I must first move the videos to my phone.

  


  I do not understand why my phone (S20) will happily play one of the videos (codec information pictured first), but presents an error "Codec not supported" when playing the other (information second).

  


  

  


  

  


  The codec information is from VLC, and as you can see, both videos have identical Codecs (H264-MPEG4).

  


  From analysing the information, the only conclusion I come to is that it has something to do with the fact that the "Decoded Format" differs across the videos. How can I change my export command on the latter so my phone supports the codec ?

  


  CONCATENATION CODE
ffmpeg -f concat -safe 0 -i {path_temp}\\clips.txt -c copy -y "{path_temp}\\{title}_a.mp4

  


  FILTER CODE
ffmpeg -i input.mp4 -filter:a "volume={volume}" -y temp.mp4"

  


  SECOND FILTER
ffmpeg -i temp.mp4 -filter_complex "[0:v]setpts={1/speed}*PTS[v];[0:a]atempo={speed}[a]" -map "[v]" -map "[a]" -y output.mp4

  


• x86 32 bit support for Accord.video.FFMPEG

  1er mars 2021, par Ravi Kanth

  Accord version 3.8.2

  


  I am using Accord, Accord.video, Accord.video.FFMPEG Dll's for capturing the screen, my code is compiled to ANYCPU, everything works fine in 64 bit machine, but I am facing issue when it comes to 32 bit machine below is exception which I am getting.

  


  Exception occurred while loading the assemblies Could not load file or assembly 'Accord.Video.FFMPEG.dll' or one of its dependencies.  is not a valid Win32 application. (Exception from HRESULT: 0x800700C1),    at System.Reflection.RuntimeAssembly.nLoadFile(String path, Evidence evidence)
   at System.Reflection.Assembly.LoadFile(String path)
   at ProHance.ProbeTray.Program.MPvcUlyJUg(Object  , ResolveEventArgs  )