Transcoding dvr-ms to mp4+Questions about QT/Quality

[grover]

Hello,

I'm transcoding dvr-ms recordings made by Windows MediaCenter 2005 from an analog PAL TV source (720x576 at 25fps, interlaced) to mp4 (x264, aac) using the following command line:

vlc.exe -I dummy --verbose 0 -vvv "dvr-ms-file" --sout=#transcode{vcodec=h264,vb=1024,acodec=mp4a,ab=192,samplerate=48000,channels=2,audio-sync,threads=2}:std{access=file,mux=mp4,url="video.mp4"} --sout-mp4-faststart --dummy-quiet vlc:quit > vlc.log

I have a couple of issues, i'd like to ask about:

1. I don't deinterlace the video, because I get really bad a/v sync issues: The audio is behind the video between 3 and 8 seconds. Is there a way to fix this? What settings should I use to deinterlace the video?

Example:
vlc.exe -I dummy --verbose 0 -vvv "dvr-ms file" --sout=#transcode{vcodec=h264,vb=1024,acodec=mp4a,ab=192,samplerate=48000,channels=2,deinterlace,audio-sync,threads=2}:std{access=file,mux=mp4,url="video.mp4"} --sout-mp4-faststart --deinterlace-mode=linear --dummy-quiet vlc:quit > vlc.log

2. The video plays back fine in QuickTime or in DirectShow based mediaplayers using CoreAVC/CoreAAC, but I'm not really happy with the video quality. Which settings would or could improve the image quality?

3. I'd like to be able to play the transcoded mp4 files with the new flash update (moviestar), however with above settings I don't get a video. I only hear the audio. What settings are required to get flash working?
--> Partially fixed see next post.

Thanks!
grover

[grover]

Ok, I've figured out why flash isn't capable of playing the transcoded video: The mp4 h264 profile is messed up. mp4box and AtomicParsely report it as unknown 5.1. I tried fixing it with mp4box by extracting all streams and creating a new one, which does repair the profile setting, but introduces a/v sync issues again.

Anyways, having the correct profile in the h264 seems to fix a lot of stuff, how can I specify the profile in the transcoding process?

[cornuz]

Hi, exactly the same problem with Flash not being able to play VLC-generated h264/mp4 files.
Please, tell me you found a solution!

[kenzo1982]

I'm getting the same problem. I can't play correctly h264/aac vlc generated media files in a flash player client through Wowza Server. Any solution?

I guess it could be related to encapsulation/container information.

VLC transcode module options to code the input from a live video/audio source (webcam):

Code: Select all

transcode{venc=x264,vcodec=x264,vb=800,scale=1,acodec=mp4a,ab=32,channels=2,samplerate=44100}

VLC std module to output to file the transcode output:

Code: Select all

std{access=file,dst="C:\videoprueba_vlc086d.mp4"}

GSpot capture from the generated file:



GSpot capture from an example h264/aac file provided with Wowza Server:



I can play the example file correctly with the flash player client. However, the client only plays the audio stream, no video is displayed. VLC plays correctly the generated file.

Thanks in advance.

[ftoppi]

Hi,

did anyone found a workaround for this problem ?

I need to transcode a lot of (customer) files for a streaming application (Wowza again) and I get a lot of "corrupted" files.
All "corrupted" files play well with VLC, mplayer, Windows Media Player, but none play OK with flash players (flowplayer 2, flowplayer 3, jw, ...). They have a green bar at the top of the image and video is flipped horizontally. Sound is OK.
I basically use the same command line as grover (no deinterlacing).

I can demux video/audio with mp4creator but can't remux them, MP4Box is not helping (same video problem, no a/v desync).

Thanks for any help.