Author Topic: H264 video with 8bit 8kHz ADPCM (CCITT) (A-Law) not playing/converting  (Read 578 times)


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Hi all,

my webcam produces a video with a H264 video stream and a ADPCM (CCITT) (A-Law) 8bit 8kHz audio stream, packed into a .AVI container.

Opening it works, but neither playing nor converting works. Playing shows a green video frame and no progress on the timeline. Hitting the info button shows correct video information but empty audio information.

My Avidemux version is 2.7.0 on a Windows 10 64bit machine. I am using the portable version from but then tried the installer version of the same (latest) version 2.7.0, neither works.

Any ideas?

The specs of the video file, taken from MediaInfo are as follows:

Complete name                            : D:\Videos\A180329_070111_070125.avi
Format                                   : AVI
Format/Info                              : Audio Video Interleave
File size                                : 1,28 MiB
Duration                                 : 17s 0 ms
Overall bit rate                         : 630 kb/s

ID                                       : 0
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : Main@L4.2
Format settings                          : CABAC / 1 Ref Frames
Format settings, CABAC                   : Ja
Format settings, RefFrames               : 1 frame
Format settings, GOP                     : M=1, N=40
Codec ID                                 : H264
Duration                                 : 17s 0 ms
Bit rate                                 : 626 kb/s
Width                                    : 1 920 Pixel
Height                                   : 1 080 Pixel
Display aspect ratio                     : 16:9
Frame rate                               : 21,000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : progressiv
Bits/(Pixel*Frame)                       : 0.014
Stream size                              : 1,27 MiB (99%)
Color range                              : Full
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.709

ID                                       : 1
Format                                   : ADPCM
Format profile                           : A-Law
Codec ID                                 : 6
Codec ID/Hint                            : CCITT
Duration                                 : 17s 0 ms
Bit rate mode                            : konstant
Bit rate                                 : 64,0 kb/s
Channel(s)                               : 1 Kanal
Sampling rate                            : 8 000 Hz
Bit depth                                : 8 bits
Stream size                              : 133 KiB (10%)

Happy with any hints.

« Last Edit: March 30, 2018, 06:28:19 PM by holyhen »


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Please provide a sample using WeTransfer, Mega or another service of your choice.


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Of course, here it comes, thanks!


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Thanks, I can confirm that virtually nothing works with the sample. ffprobe/ffplay spits tons of errors and warnings about the file (non-interleaved AVI, frame headers which can't be decoded, missing frames etc.). As decoding fails, the logic responsible for enabling seeking in AVIs without B-frames with H.264 video inside gets skipped, so we end up with an unplayable, not seekable video. I doubt that anything can be done in this case, however.


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Ok, I did some more tests. Following observations:
  • Tried these converters, all can process the video: TEncoder, Vidcoder, (Handbrake Engine), XMediaRecode.
  • Playing with VLC also works.
The audio of the video seems very broken:
  • Opening the video directly with Audacity works but shows no waveworm, not even a millisecond.
  • Extracting the audio with Pazera Free Audio Extractor results in a wav file of 92 bytes, obviously containing only metadata, but no wave data.
So I solved this by using MKVToolNixGUI to multiplex the video into a MKV container, copying video but leaving out audio. The resulting MKV file imports fine into Avidemux.

If this gives hints of any kind to maybe make Avidemux import such a file nevertheless, I'd be more than happy.
« Last Edit: April 02, 2018, 09:25:05 AM by holyhen »