#14 Output frame buffer too small

x264vfw
closed
nobody
None
1
2014-07-22
2013-09-27
Anonymous
No

Graph: Webcam->x264vfw->GDCL Muxer->file Writer. start-stop-pause gives error messages "Output frame buffer too small".

see attachments for FilterGraph/Error Messages

Discussion

  • BugMaster
    BugMaster
    2013-09-27

    Yes, I have seen this (problem with stop/start in GraphStudio without reconnecting filters) before. The problem here is that is not exactly bug of x264vfw but bug somewhere in DirectShow filters. I am not sure which of the filters to blame:
    - Microsoft's DirectShow wrapper for VFW i.e. AVI Compressor (bar with x264vfw in GraphStudio)
    or
    - Source filter i.e. Integrated Webcam in your case
    or
    - GraphStudio itself (that it start/stops without reconnecting or not updating something).

    In result I get ICM_COMPRESS message where icc->lpbiOutput->biSizeImage is incorrect (probably size of last encoded frame and not the buffer size which is set by good apps before every ICM_COMPRESS message.
    Currently there is already workaround for the buggy apps that don't update this field for every ICM_COMPRESS message but at least have it correct at first after ICM_COMPRESS_BEGIN message. But it doesn't work in your case because this remembered buffer size is cleared after ICM_COMPRESS_BEGIN (due stop/start) in prepare to the correct one.

    So only workarounds I can suggest and need feedback:
    - don't clear remembered size after ICM_COMPRESS_BEGIN which is not very good because in between you could changed other params and most dangerous reallocate this output buffer (but keep buffer pointer the same)
    - add some probably hidden option (i.e. not visible like simple value in windows registry) to fully disable this size check in x264vfw. At user who set it will be the one to take risk of buffer overrun / crash / etc in the case of buggy app providing buffer not large enough to write output. Also I am not sure if "Load Defaults" button should reset this hidden flag also.

     
  • BugMaster
    BugMaster
    2014-07-22

    Should be probably fixed in 39_2453bm_40246 release.

     


Anonymous


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