alpha channel not preserved when transcoding
|Reported by:||matteosistisette||Owned by:||michael|
|Blocking:||Reproduced by developer:||no|
|Analyzed by developer:||no|
When transcoding an flv file which has an alpha channel into a video or image file using codecs that support alpha channel (such as h264, or Apple Animation (qtrle), or PNG) the alpha channel is lost and the output video has an opaque background.
An example flv input file with transparency can be downloaded from http://totalwebvideo.com/pitchalt.flv
It has alpha channel. H264, Apple Animation and PNG all support alpha channel, so if any of these is used as the encoder and if the input video has alpha channel, the alpha channel should be preserved by default when transcoding.
Change History (3)
comment:1 Changed 5 years ago by michael
- Component changed from FFmpeg to undetermined
- Priority changed from critical to normal
comment:2 Changed 5 years ago by cehoyos
- Resolution set to worksforme
- Status changed from new to closed