hellfred
5th February 2006, 11:02
Hi folks
I have searched this forum and the FAQs and did not find any answeres up to now. I have some ideas how to proceed, but I need your help and advice.
Problem:
I have an analog capture with poor sync between audio and video. The audio (uncompressed 2 channels for stereo sound) is delay approx. 450 ms in the beginning, and after 2:02 hours (end of clip) the delay increased to over 2 seconds. The video is compressed with libavcodec mjpec codec. The capture is stored in an avi file with a size of approx. 8 GB.
Target:
I want to sync the audio to the video, cut the commercials out of the video and compress the video with XviD to shrink down the size to approx 700 MB. As the quality is already low, I want to compress video just once. So I want to crop, resize and add noise reduction to the video.
I had a look into AviSynths audio streaming possiblilty but I did not see any way to stretch the audio. So I had a look at VirtualDubMod v1.5.10.
Preparation and Ideas:
The audio was demuxed to a wav file. I can open the avi via an AviSynth script that will do the cropping, denoising and filtering:
AVISource("I:\cap\Galactica2.avi",audio=false)
Crop(6,56,-6,-60)
FluxSmoothT(4)
BicubicResize(512,304,0,0.5)
The audio is added as new Stream *Stream->Stream List->Add). I have enabled "Full processing mode" and "Use advanced filtering". Filter setup: input->stretch(by 1.0003)->output.
The initial delay of 450 ms is taken care of by chooseing Interleaving->AudioSkrewCorrection->450ms
Next step would be, either to cut out the comercial in VDubMod directly, chose Video->Fast recompress, setup and XviD and give it a try. But it will take quite a while, I do not know if cutting the comerials will screw up the sync again because the Audio in wav does not get cut, too. And even if i succeed, but find that the delay and stretch factor where not ideal, I have to redo setting the parameter and encode once more. Proceeding like this will take ages to come up with an acceptable result.
Other idea is to not cut clips, choose Video->Direct Stream Copy and save the audio and video to a new avi file. But will that change anything in the source at all?
Hellfred
I have searched this forum and the FAQs and did not find any answeres up to now. I have some ideas how to proceed, but I need your help and advice.
Problem:
I have an analog capture with poor sync between audio and video. The audio (uncompressed 2 channels for stereo sound) is delay approx. 450 ms in the beginning, and after 2:02 hours (end of clip) the delay increased to over 2 seconds. The video is compressed with libavcodec mjpec codec. The capture is stored in an avi file with a size of approx. 8 GB.
Target:
I want to sync the audio to the video, cut the commercials out of the video and compress the video with XviD to shrink down the size to approx 700 MB. As the quality is already low, I want to compress video just once. So I want to crop, resize and add noise reduction to the video.
I had a look into AviSynths audio streaming possiblilty but I did not see any way to stretch the audio. So I had a look at VirtualDubMod v1.5.10.
Preparation and Ideas:
The audio was demuxed to a wav file. I can open the avi via an AviSynth script that will do the cropping, denoising and filtering:
AVISource("I:\cap\Galactica2.avi",audio=false)
Crop(6,56,-6,-60)
FluxSmoothT(4)
BicubicResize(512,304,0,0.5)
The audio is added as new Stream *Stream->Stream List->Add). I have enabled "Full processing mode" and "Use advanced filtering". Filter setup: input->stretch(by 1.0003)->output.
The initial delay of 450 ms is taken care of by chooseing Interleaving->AudioSkrewCorrection->450ms
Next step would be, either to cut out the comercial in VDubMod directly, chose Video->Fast recompress, setup and XviD and give it a try. But it will take quite a while, I do not know if cutting the comerials will screw up the sync again because the Audio in wav does not get cut, too. And even if i succeed, but find that the delay and stretch factor where not ideal, I have to redo setting the parameter and encode once more. Proceeding like this will take ages to come up with an acceptable result.
Other idea is to not cut clips, choose Video->Direct Stream Copy and save the audio and video to a new avi file. But will that change anything in the source at all?
Hellfred