Hi list,
I have a patch that syncs multi-channel audio with video by passing frame numbers to pix_film. These frame numbers are generated by the audio playback. With HD video however and scenes including smooth movements, the image becomes a little jittery and a bit blurred. I tried completely disabling the audio but it made no effect. When audio is enabled and I run the pix_film with an "auto 1" message, playback is excellent.
I'll experiment now to see if lip-sync can be maintained without propper frame-sync, since my clips have at maximum 3min duration.
I'm wondering though if anyone else had come across this blurring?
I'm using by the way, a heavily butchered version of Hans-Christoph's framesync (and an old version of it). However, even if don't use the framesync patches and pass a frame count generated with metro and a counter at the correct rate of 30fps - the blurring still happens.
Suggestions most welcome!
Cheers,
Iain
Forgot to mention i'm using Ubuntu 11.10 and the video files are 30 fps with the codec H.264 / AVC
Also, while sending an "auto 1" message to pix_film gives smooth playback, the file plays perhaps 30% slow. This doesn't seem to be a CPU issue as the cpu is running between 20 and 30% while playing the file.
Iain
On Mon, 2012-07-02 at 17:14 -0300, Iain Mott wrote:
Hi list,
I have a patch that syncs multi-channel audio with video by passing frame numbers to pix_film. These frame numbers are generated by the audio playback. With HD video however and scenes including smooth movements, the image becomes a little jittery and a bit blurred. I tried completely disabling the audio but it made no effect. When audio is enabled and I run the pix_film with an "auto 1" message, playback is excellent.
I'll experiment now to see if lip-sync can be maintained without propper frame-sync, since my clips have at maximum 3min duration.
I'm wondering though if anyone else had come across this blurring?
I'm using by the way, a heavily butchered version of Hans-Christoph's framesync (and an old version of it). However, even if don't use the framesync patches and pass a frame count generated with metro and a counter at the correct rate of 30fps - the blurring still happens.
Suggestions most welcome!
Cheers,
Iain
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More info:
GEM: ver: 0.93.SVN rev4518
[pix_film]: gmerlin support [pix_film]: quicktime4linux support [pix_film]: MPEG3 support [pix_film]: aviplay support
On Mon, 2012-07-02 at 18:19 -0300, Iain Mott wrote:
Forgot to mention i'm using Ubuntu 11.10 and the video files are 30 fps with the codec H.264 / AVC
Also, while sending an "auto 1" message to pix_film gives smooth playback, the file plays perhaps 30% slow. This doesn't seem to be a CPU issue as the cpu is running between 20 and 30% while playing the file.
Iain
On Mon, 2012-07-02 at 17:14 -0300, Iain Mott wrote:
Hi list,
I have a patch that syncs multi-channel audio with video by passing frame numbers to pix_film. These frame numbers are generated by the audio playback. With HD video however and scenes including smooth movements, the image becomes a little jittery and a bit blurred. I tried completely disabling the audio but it made no effect. When audio is enabled and I run the pix_film with an "auto 1" message, playback is excellent.
I'll experiment now to see if lip-sync can be maintained without propper frame-sync, since my clips have at maximum 3min duration.
I'm wondering though if anyone else had come across this blurring?
I'm using by the way, a heavily butchered version of Hans-Christoph's framesync (and an old version of it). However, even if don't use the framesync patches and pass a frame count generated with metro and a counter at the correct rate of 30fps - the blurring still happens.
Suggestions most welcome!
Cheers,
Iain
Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
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The h.264 codec is not the best one for GEM. Try converting it to Photo or Motion JPEG.
On Mon, Jul 2, 2012 at 5:19 PM, Iain Mott mott@reverberant.com wrote:
Forgot to mention i'm using Ubuntu 11.10 and the video files are 30 fps with the codec H.264 / AVC
Also, while sending an "auto 1" message to pix_film gives smooth playback, the file plays perhaps 30% slow. This doesn't seem to be a CPU issue as the cpu is running between 20 and 30% while playing the file.
Iain
On Mon, 2012-07-02 at 17:14 -0300, Iain Mott wrote:
Hi list,
I have a patch that syncs multi-channel audio with video by passing frame numbers to pix_film. These frame numbers are generated by the audio playback. With HD video however and scenes including smooth movements, the image becomes a little jittery and a bit blurred. I tried completely disabling the audio but it made no effect. When audio is enabled and I run the pix_film with an "auto 1" message, playback is excellent.
I'll experiment now to see if lip-sync can be maintained without propper frame-sync, since my clips have at maximum 3min duration.
I'm wondering though if anyone else had come across this blurring?
I'm using by the way, a heavily butchered version of Hans-Christoph's framesync (and an old version of it). However, even if don't use the framesync patches and pass a frame count generated with metro and a counter at the correct rate of 30fps - the blurring still happens.
Suggestions most welcome!
Cheers,
Iain
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http://lists.puredata.info/listinfo/pd-list
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Thanks Chris and Olivier. I tried your suggestions (mjpeg conversion and keyframes on each frame) however they didn't seem to make much of a difference. I did get an improvement after recompiling GEM and adding some extra libraries before the config step. Playback is still proving too jittery with some images such as slowly rising smoke (which plays fine in vlc).
About the encoding settings: it is someone else that is encoding the video so i'm not sure about the settings. I can ask for the videos to be re-encoded - but will continue to try and convert the files to see what works.
I've attached a print out of the configuration output when compiling GEM
Thanks again,
Iain
On Mon, 2012-07-02 at 17:37 -0400, chris clepper wrote:
The h.264 codec is not the best one for GEM. Try converting it to Photo or Motion JPEG.
On Mon, Jul 2, 2012 at 5:19 PM, Iain Mott mott@reverberant.com wrote: Forgot to mention i'm using Ubuntu 11.10 and the video files are 30 fps with the codec H.264 / AVC
Also, while sending an "auto 1" message to pix_film gives smooth playback, the file plays perhaps 30% slow. This doesn't seem to be a CPU issue as the cpu is running between 20 and 30% while playing the file. Iain On Mon, 2012-07-02 at 17:14 -0300, Iain Mott wrote: > Hi list, > > I have a patch that syncs multi-channel audio with video by passing > frame numbers to pix_film. These frame numbers are generated by the > audio playback. With HD video however and scenes including smooth > movements, the image becomes a little jittery and a bit blurred. I tried > completely disabling the audio but it made no effect. When audio is > enabled and I run the pix_film with an "auto 1" message, playback is > excellent. > > I'll experiment now to see if lip-sync can be maintained without propper > frame-sync, since my clips have at maximum 3min duration. > > I'm wondering though if anyone else had come across this blurring? > > I'm using by the way, a heavily butchered version of Hans-Christoph's > framesync (and an old version of it). However, even if don't use the > framesync patches and pass a frame count generated with metro and a > counter at the correct rate of 30fps - the blurring still happens. > > Suggestions most welcome! > > Cheers, > > Iain > > > _______________________________________________ > Pd-list@iem.at mailing list > UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list _______________________________________________ Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
Le 02/07/2012 23:19, Iain Mott a écrit :
Forgot to mention i'm using Ubuntu 11.10 and the video files are 30 fps with the codec H.264 / AVC
What are your encoding settings? I always use a GOP size of 1 with h264, otherwise you might encounter temporal interpolation artefacts at playtime. Have a look at the Blender 3D snapshot at the bottom of http://fr.flossmanuals.net/performance-audiovisuelle-et-pratique-du-vjing/ch...
There is also a very nice H264 encoder called h264enc which might help you http://h264enc.sourceforge.net/
If you'd rather use a gui, try http://ekd.tuxfamily.org/index.php/Accueil/AccueilEnglish
Here are a command line which has proven useful:
ffmpeg -an -y -i DSCN0716.MOV -r 25 -s 960x540 -f avi -vcodec libx264 -b:v 50000k -g 1 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -b_strategy 1 /bigfiles/DSCN0176.mp4
key parameter is the -g option , set it to one so to have a keyframe every frame, hence no interpolation at all. If you're rether the datamosh guy, just set very very high ;-) such as this one courtesy BenJah :
ffmpeg -i input_video.mov -g 250 -sc_threshold 1000000000 -vcodec libxvid output_video.mp4
All these are compiled on the French-speaking Labomédia wiki:
http://wiki.labomedia.org/index.php/Le_DataMoshing
Also, while sending an "auto 1" message to pix_film gives smooth playback, the file plays perhaps 30% slow. This doesn't seem to be a CPU issue as the cpu is running between 20 and 30% while playing the file.
Auto 1 doesnt always detect the right framerate as I have experienced. Pix_movie is more reliable.
Cheers
OH
Iain
On Mon, 2012-07-02 at 17:14 -0300, Iain Mott wrote:
Hi list,
I have a patch that syncs multi-channel audio with video by passing frame numbers to pix_film. These frame numbers are generated by the audio playback. With HD video however and scenes including smooth movements, the image becomes a little jittery and a bit blurred. I tried completely disabling the audio but it made no effect. When audio is enabled and I run the pix_film with an "auto 1" message, playback is excellent.
I'll experiment now to see if lip-sync can be maintained without propper frame-sync, since my clips have at maximum 3min duration.
I'm wondering though if anyone else had come across this blurring?
I'm using by the way, a heavily butchered version of Hans-Christoph's framesync (and an old version of it). However, even if don't use the framesync patches and pass a frame count generated with metro and a counter at the correct rate of 30fps - the blurring still happens.
Suggestions most welcome!
Cheers,
Iain
Pd-list@iem.at mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
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On 2012-07-02 23:19, Iain Mott wrote:
Forgot to mention i'm using Ubuntu 11.10 and the video files are 30 fps with the codec H.264 / AVC
Also, while sending an "auto 1" message to pix_film gives smooth playback, the file plays perhaps 30% slow. This doesn't seem to be a CPU issue as the cpu is running between 20 and 30% while playing the file.
in "auto 1" mode, Gem will increment to the "next" frame in each render tick. "next" means that #125 will follow #124 regardless of the actual fps of the video. since your video is encoded with 30fps and the default tick-time in Gem is 20fps you will play the file at a reduced speed. the simplest solution is to raise Gem's framerate.
as others have pointed out, the "blurring" will most likely come from inter-frame compression where you are trying to access non-keyframes and the used backend (most likely gmerlin, according to your settings) does a bad job at reconstructing the image.
fgamsdr IOhannes
On Tue, 2012-07-03 at 09:15 +0200, IOhannes m zmoelnig wrote:
Gem is 20fps you will play the file at a reduced speed. the simplest solution is to raise Gem's framerate.
as others have pointed out, the "blurring" will most likely come from inter-frame compression where you are trying to access non-keyframes and the used backend (most likely gmerlin, according to your settings) does a bad job at reconstructing the image.
Thanks IOhannes, I didn't know about the 20fps default. If gmerlin does a poor job, how can enlist the services of a better backend? Is this a matter of using a different codec or do I have to recompile with certain config options? Cheers, Iain
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On 2012-07-03 18:36, Iain Mott wrote:
On Tue, 2012-07-03 at 09:15 +0200, IOhannes m zmoelnig wrote:
Gem is 20fps you will play the file at a reduced speed. the simplest solution is to raise Gem's framerate.
as others have pointed out, the "blurring" will most likely come from inter-frame compression where you are trying to access non-keyframes and the used backend (most likely gmerlin, according to your settings) does a bad job at reconstructing the image.
Thanks IOhannes, I didn't know about the 20fps default. If gmerlin does a poor job, how can enlist the services of a better backend? Is this a matter of using a different codec or do I have to recompile with certain config options?
i'm not saying that gmerlin _is_ doing a bad job. afaik, it does the best job _in general_ (supports most formats, allows to access random-access, ...) whether it does a bad job in the specific case i cannot really tell, but it seems so.
anyhow, you can select a different backend using yet another parameter to the "open" message: [open foo.mov RGBA quicktime4linux( should open "foo.mov" in the RGBA-space using "quicktime4linux" (rather than gmerlin).
afair, the backend is merely a suggestion, and if the desired backend is not able to open the given file, it will fallback to the default behaviour.
fgamsdr IOhannes