Beiträge von spreeni

  • Vokoder 11.x - zscale filter stretch images

    Hello,

    I used Voukoder 10.2 for encoding h264 mp4 videos in 1280x720 for web purposes. I usually render them in Adobe Premiere and in DaVinci Resolve 17. The scaling of the timeline resolution to the desired 720p is done by voukoder by the internal zscale filter (lanczos). This gives me the best result, much better than scaling it in the editing software.

    After upgrading to the 11.1 version the zscale encoded clips look somehow shrinked or - in some parts of the picture - they look a bit stretched. It looks like zscale is skipping some lines. This happens with the current connector versions in Adobe premiere and in Resolve - after reinstalling the older 10.2 version (connector plugins staying the same) everything's working normal again. So it must have something to do with changes of the 11.x version. I also checked version 11beta3 - same behavior.

    Can someone confirm this behavior? Thank you!

  • Exported sequences to H264 mp4 - first two frames are missing

    I did some more tests and I found out, that the param B-Pyramid is the cause of the missing first and second frame. If I set it to "disable", sequences are encoded completely. If it is set to "strict" or "normal" (or left unchecked as default) the first two frames are cut off.

    So now I know, why - and it is probably no plug-in bug. Btw, what is the recommended setting for B-Pyramid? Normal, strict or better disabled?

  • A better AAC encoder: FDK-AAC

    I did some tests with a sequence of white noise. I made a screenshot of the spectralview in Audition. The results are attached as PNG-pictures:

    01-uncompreessed.png: Uncompressed - this is what it shoul look like


    02-AAC-ffmpg_CBR_320.png: The native FFMPG AAC Encoder at 320kbit (48Khz stereo) - look at these "glitches"

    03-AAC-ffmpg_CBR_384.png: Same settings but slightly higher bitrate (384kbit) - noticeably better quality

    04-fdkAAC_CBR_320.png: fdk AAC Encoder at 320kbit, very good quality, but frequencies above 17Khz are cut

    05-AAC_x264Pro-plug-in: AAC Encoder of the x264Pro plug-in. I don't know what encoder is used here but it looks outstanding

    So my result is: For best AAC quality in voukoder use the native FFMPG AAC encoder at higher bitrates (min 384) or use the the fdk encoder and live without the 17.000+ frequencies. After some rock concerts these frequencies are blows away, anyway ;) )

  • A better AAC encoder: FDK-AAC

    Thank you for response, I tried to find some more informations about it in the ffmpg wiki, but unfortunately it makes it not quite clear:

    https://trac.ffmpeg.org/wiki/Encode/AAC

    Zitat

    The Fraunhofer FDK AAC codec library. This is currently the highest-quality AAC encoder available with ffmpeg.

    and then, later

    Zitat

    For AAC-LC: as of 2017 this is no longer necessarily the case. The built in aac encoder is quite good.

    Fo me it sounds like the built in acc encoder makes no difference in AAC-LC, but it still does in main profile. However, I think I have to do some tests of my own, and yes, you're right, lossless is the best but ...not so efficient.