h264 + placebo + profile high: playback distortion with DXVA
h264 + placebo + profile high: playback distortion with DXVA
My playback setup: XBMC with video hardware acceleration enabled (=DXVA2) on Win7
Now, if I encode a sample with “preset placebo + profile high” or “preset veryslow + profile high”, I get distortion in my picture (purple-like color everywhere with proper keyframes every 5-10sec). This is not the case with other samples encoded with “faster” presets.
As far as I see, this is due to enabled DXVA2, because when I disable it (software decoding), I get perfect picture, even with placebo-encoded samples.
But now I am confused. Doesn’t “--profile high” assure me that my sample should be playable with DXVA2 enabled?? It is an 1000kbps stream. (cf. Intel® HD Graphics: Support H.264/AVC decode acceleration High Profile @ L4.1 up to 40 Mbps. I am using Intel Core i3-550.)
Can someone explain? As far as I see, this is a bug (?).
Kind regards,
Davor
Now, if I encode a sample with “preset placebo + profile high” or “preset veryslow + profile high”, I get distortion in my picture (purple-like color everywhere with proper keyframes every 5-10sec). This is not the case with other samples encoded with “faster” presets.
As far as I see, this is due to enabled DXVA2, because when I disable it (software decoding), I get perfect picture, even with placebo-encoded samples.
But now I am confused. Doesn’t “--profile high” assure me that my sample should be playable with DXVA2 enabled?? It is an 1000kbps stream. (cf. Intel® HD Graphics: Support H.264/AVC decode acceleration High Profile @ L4.1 up to 40 Mbps. I am using Intel Core i3-550.)
Can someone explain? As far as I see, this is a bug (?).
Kind regards,
Davor
Re: h264 + placebo + profile high: playback distortion with
x264 presets/tunes and HandBrakedavor wrote:(cf. Intel® HD Graphics: Support H.264/AVC decode acceleration High Profile @ L4.1 up to 40 Mbps. I am using Intel Core i3-550.)
H.264 Profiles
H.264 Levels
Re: h264 + placebo + profile high: playback distortion with
Thank you for your instructive post. Had read about profiles, but not about levels…Rodeo wrote:H.264 Levelsdavor wrote:(cf. Intel® HD Graphics: Support H.264/AVC decode acceleration High Profile @ L4.1 up to 40 Mbps. I am using Intel Core i3-550.)
As far as I understand, I should set these extra options to make placebo L4.1 compliant:
--encopts "ref=4:vbv-bufsize=78125:vbv-maxrate=62500"
I have tried this, and it works now with DXVA2 enabled.
But still, I don’t understand why there is no simple option like “--x264-level” as there is “--x264-profile”. Basically, what I need, and probably many users also, is to select a profile and level, and select the highest preset (i.e. placebo) which gives me the best quality given a certain bitrate.
Kind regards,
Davor
EDIT: I think --encopts "level=4.1:vbv-bufsize=78125:vbv-maxrate=62500" would also work.
EDIT2: It gives a warning that ref is set to 16.
Last edited by davor on Mon Mar 05, 2012 4:13 pm, edited 1 time in total.
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Re: h264 + placebo + profile high: playback distortion with
Not to go off topic, but does "placebo" mean something different with regards to x264?
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Re: h264 + placebo + profile high: playback distortion with
As far as I can see from x264 presets/tunes and HandBrake, they are based on the x264 presets. So they are equivalent, and I think one would get the same results with --x264-preset placebo as with --encopts "preset=placebo".Smithcraft wrote:Not to go off topic, but does "placebo" mean something different with regards to x264?
So I think (hope) '--x264-preset placebo' is simply translated to '--encopts "preset=placebo"' and passed to the x264 encoder. Same holds for '--x264-tune' option.
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Re: h264 + placebo + profile high: playback distortion with
That's not quite what I'm asking. Going through the settings, it looks like it means exactly what I thought.
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Re: h264 + placebo + profile high: playback distortion with
Because the function to ensure level compliance is not implemented in libx264 yet? We can't use a function that doesn't exist.davor wrote:But still, I don’t understand why there is no simple option like “--x264-level” as there is “--x264-profile”.
When x264 adds it (there are plans to do so), we'll add support for it to HandBrake (in the CLI).
Re: h264 + placebo + profile high: playback distortion with
No. "preset" is not a valid libx264 option. We need to use a dedicated function (x264_param_default_preset for presets and tunes, and x264_param_apply_profile for profiles). Otherwise there's be absolutely no need for dedicated options (you'd just use --encopts).davor wrote:So I think (hope) '--x264-preset placebo' is simply translated to '--encopts "preset=placebo"' and passed to the x264 encoder. Same holds for '--x264-tune' option.
Re: h264 + placebo + profile high: playback distortion with
We might be adding our own variant of x264_param_apply_level instead.Rodeo wrote:Because the function to ensure level compliance is not implemented in libx264 yet? We can't use a function that doesn't exist.davor wrote:But still, I don’t understand why there is no simple option like “--x264-level” as there is “--x264-profile”.
When x264 adds it (there are plans to do so), we'll add support for it to HandBrake (in the CLI).
If you know how to build from source: https://reviews.handbrake.fr/r/278/
Re: h264 + placebo + profile high: playback distortion with
https://trac.handbrake.fr/changeset/4534
https://trac.handbrake.fr/changeset/4535
Will be available in tomorrow's nightly.
https://trac.handbrake.fr/changeset/4535
Will be available in tomorrow's nightly.
Re: h264 + placebo + profile high: playback distortion with
Looks interesting. Thank you!Rodeo wrote:https://trac.handbrake.fr/changeset/4534
https://trac.handbrake.fr/changeset/4535
Will be available in tomorrow's nightly.
Re: h264 + placebo + profile high: playback distortion with
I am still experiencing playback distortion when using 16 reference frames with DVD resolution. According tot this page 16 reference frames is well within the 4.1 spec, so it should work...
If I use 11 reference frames I get no playback distortion.
Any idea what might be wrong this time?
If I use 11 reference frames I get no playback distortion.
Any idea what might be wrong this time?
Re: h264 + placebo + profile high: playback distortion with
Nope. But TBH anything above 5-8 is overkill for most content.
Re: h264 + placebo + profile high: playback distortion with
I have some encodings on 720p with 9ref, and they work just fine.Rodeo wrote:Nope. But TBH anything above 5-8 is overkill for most content.
But 576p seems problematic. Even at 11ref I see glitches.