Seek Issues in WebM (VP8 IVF/OGG) File

[geocine]

I have a file downloaded from the web this is the media below.

    General
    Format                                   : WebM
    Format version                           : Version 2
    File size                                : 10.3 MiB
    Duration                                 : 6mn 30s
    Overall bit rate mode                    : Variable
    Overall bit rate                         : 222 Kbps
    Movie name                               : Untitled
    Writing application                      : Lavf53.13.0
    Writing library                          : Lavf53.13.0
    
    Video
    ID                                       : 1
    Format                                   : VP8
    Codec ID                                 : V_VP8
    Duration                                 : 6mn 30s
    Bit rate                                 : 76.6 Kbps
    Width                                    : 1 024 pixels
    Height                                   : 768 pixels
    Display aspect ratio                     : 4:3
    Frame rate mode                          : Constant
    Frame rate                               : 15.000 fps
    Compression mode                         : Lossy
    Bits/(Pixel*Frame)                       : 0.006
    Stream size                              : 3.57 MiB (34%)
    Language                                 : English
    Default                                  : Yes
    Forced                                   : No
    
    Audio
    ID                                       : 2
    Format                                   : Vorbis
    Format settings, Floor                   : 1
    Codec ID                                 : A_VORBIS
    Duration                                 : 6mn 30s
    Bit rate mode                            : Variable
    Bit rate                                 : 128 Kbps
    Channel(s)                               : 2 channels
    Sampling rate                            : 44.1 KHz
    Compression mode                         : Lossy
    Stream size                              : 5.96 MiB (58%)
    Writing library                          : libVorbis (Schaufenugget) (20101101 (Schaufenugget))
    Language                                 : English
    Default                                  : Yes
    Forced                                   : No
    Writing application                      : Lavc53.19.0

I tried transcoding the file into MKV but no luck I could not get it to fix the seek issues:

    
    mkvextract tracks file.webm 0:file.ivf
    mkvextract tracks file.webm 1:file.ogg
    mkvmerge -o file.mkv file.ivf file.ogg

I also tried fixing the indexes using mencoder but it got worse.

    mencoder input.mkv -idx -ovc copy -oac copy -o output.mkv

I also tried Metorite

Meteorite is MKV / Matroska file repair engine. That repairs MKV files and can repair MKV files still downloading from internet.

I was able to seek but the video halts after moving the video sliders , the audio remains normal.

Do you know other ways to fix the seek issues?

[TSJNachos]

I would try re-downloading the WebM file. It sounds like something got messed up during the transfer. If all fails again, perhaps you could download the video in another format, assuming one's available from wherever you got the WebM file in the first place.

[geocine]

The WebM file is complete and encoding it into an MP4 solves the seek issues. However, I would like to know if I could fix the seek issues without re-encoding the file.

[El Heggunte]

Seeking issues generally are caused by a bad MKV splitter.

JMO, but since WebM sucks , I would (try to, at least) rewrap the VP8 stream in an AVI container, and then remux to MKV (by using the "V_MS/VFW/VP80" mode) with the Vorbis audio track.

[geocine]

@El Heggunte

Thank you for your response. May you please advice as to what tools will I be using in order to go about what you suggested?

I have tried this though

ffmpeg -i file.webm -vcodec copy file.avi

I could now seek through my file. Question though, does the video gets re-encoded when I do this?

[pandy]

@El Heggunte

Thank you for your response. May you please advice as to what tools will I be using in order to go about what you suggested?

I have tried this though

ffmpeg -i file.webm -vcodec copy file.avi

I could now seek through my file. Question though, does the video gets re-encoded when I do this?

No -vcodec copy means that video is just copied without any modifications

[geocine]

Thanks @pandy,

By the way, I want to use AAC for the audio

ffmpeg -i file.webm -vcodec copy -acodec libvo_aacenc -b:a 128k -file.avi

Whenever I use this I get this error below:



I don't know if -b:a isn't really supported so I revise my command and do this:

ffmpeg -i "file.webm" -v codec copy -acodec libvo_aacenc -ab 128k file.avi

However I get an error regarding libvo_aacenc.



I am using the latest Zeranoe FFmpeg build

FFmpeg git-1a104bf 32-bit Static (Latest) (2012-10-10)

According to the Readme . It was compiled with the configuration --enable-libvo-aacenc . so this shouldn't be a problem.

Any idea guys?

[pandy]

Perhaps Readme is not correct - i don't see libvo-aacenc on list

[geocine]

Thanks pandy for helping out, I have solved the question above by fixing conflicting windows paths on my system.