Interlaced encoding troubles

[bkman]

I'm having some problems with using x264 with the interlaced encoding mode. I'm not sure if it is an encoder or decoder issue, but I suspect the former.

The first problem is that the resulting video crashes mplayer, and stalls ffdshow. I was under the impression that libavcodec supported interlaced AVC..? CoreAVC does play it, except for the odd glitches in the video at seemingly random times. I can upload a sample if necessary.

Is this a bug in x264?

[akupenguin]

libavcodec supports interlaced H.264, but only mod32 height. (strictly: height%32==0 || height%32>=18. so 1080i works, 1072i doesn't.) I know exactly where the bug is, but not how to fix it. (Random aside: this is one of those reasons I'm glad x264 is not part of libavcodec: I can make such changes in x264 without worrying about how they interact with the other codecs.)

[Jay Bee]

CoreAVC does play it, except for the odd glitches in the video at seemingly random times

My own experiments indicate that none of these glitches occur if you don't disable "DCT decimate" and don't set any "RDO" modes.

For playback I would recommend using CoreAVC as it can use your GPU hardware to do high quality, automatic deinterlacing (set CoreAVC to "directshow deinterlacing", needs v1.3).

[bkman]

A mod32 height fixed the libavcodec crashes, but the occasional artifacts still remain, even with RDO modes disabled.

My commandline is --crf 20 --ref 5 --mixed-refs --no-fast-pskip --bframes 3 --b-pyramid --bime --weightb --direct auto --filter -2,-1 --trellis 1 --analyse all --8x8dct --vbv-maxrate 25000 --me umh --thread-input --sar 1792:1215 --progress --interlaced

Is there anything else I have to disable to avoid the artifacts?

[Crisidelm]

Since when CoreAVC takes advantage of GPU hardware?

[Jay Bee]

Is there anything else I have to disable to avoid the artifacts?

Those are the only ones I found. You'll have to trial and error the settings yourself. Please report if you find anything.

Since when CoreAVC takes advantage of GPU hardware?

From version 1.1 I think. But it didn't work properly until 1.3. I didn't say it uses the GPU to do decoding BTW, only deinterlacing. ;)