Square Aspect Ratio when watching or transcoding a stream.
Posted: 14 Apr 2010 00:44
I have a square aspect ratio on an h264 stream that is captured by Quicktime broadcaster, then transcoded by VLC, and then segmented for iPhone.
Points of interest:
- I am capturing with QTB and sending the stream as a unicast to 127.0.0.1:5432
- Then I export a "meeting.sdp" file containing the stream settings so vlc can receive the stream.
- I "Advanced Open" that "meeting.sdp" file with VLC and treat as pipe and stream by UTP to 127.0.0.1:50000 , (transcoding the video to h264 and not transcoding the audio, setting the h264 codec to use "Access unit delimiters" in the prefs)
- Apple "Media Segmenter" receives the UTP 127.0.0.1:50000 stream from VLC, chops it up and sends it to Apache to server.
- wa la , I am streaming html5 video to our iPhones and iPads !!!
- BUT the aspect ratio is 1:1 square. the 4:3 source is being squeezed to tall and skinny 1:1
While troubleshooting:
- When I use QTB to unicast or multicast streams directly to QT clients all is fine, 4:3 aspect ratio (I create an .sdp file in QTB and send it to the QT clients to play)
- Temporarily with VLC I "PLAYED" instead of transcoding the QTB stream, it played at 1:1 until I manually changed it to 4:3 in the VLC player "Video -> Aspect-ratio" menu.
So, I can force VLC to "play" it in 4:3, but I need (and do not know) to force it into 4:3 when transcoding and streaming. It always comes out 1:1 square.
Any Ideas? I have spent days looking before I asked.
Thanks, Ken
Points of interest:
- I am capturing with QTB and sending the stream as a unicast to 127.0.0.1:5432
- Then I export a "meeting.sdp" file containing the stream settings so vlc can receive the stream.
- I "Advanced Open" that "meeting.sdp" file with VLC and treat as pipe and stream by UTP to 127.0.0.1:50000 , (transcoding the video to h264 and not transcoding the audio, setting the h264 codec to use "Access unit delimiters" in the prefs)
- Apple "Media Segmenter" receives the UTP 127.0.0.1:50000 stream from VLC, chops it up and sends it to Apache to server.
- wa la , I am streaming html5 video to our iPhones and iPads !!!
- BUT the aspect ratio is 1:1 square. the 4:3 source is being squeezed to tall and skinny 1:1
While troubleshooting:
- When I use QTB to unicast or multicast streams directly to QT clients all is fine, 4:3 aspect ratio (I create an .sdp file in QTB and send it to the QT clients to play)
- Temporarily with VLC I "PLAYED" instead of transcoding the QTB stream, it played at 1:1 until I manually changed it to 4:3 in the VLC player "Video -> Aspect-ratio" menu.
So, I can force VLC to "play" it in 4:3, but I need (and do not know) to force it into 4:3 when transcoding and streaming. It always comes out 1:1 square.
Any Ideas? I have spent days looking before I asked.
Thanks, Ken