Subtitles in Gstreamer

[stéphanenoblet]

Dear,

I'm trying to use gstreamer to decode 4K video with subtitles.

It work fine with Full HD video (1080p) with the command :

gst-launch-1.0 playbin uri=file:///home/root/Sintel.2010.1080p.mkv

But when I use it on a Ultra HD video (4K), the CPU become overloaded, and the video fail.

I suppose gstreamer try to add subtitle into video without hardware acceleration.

Are those type of issue encountered on I.MX6 ?

Does the gstreamer subtitle with hardware acceleration exists ?

Thanks,

Stéphane

[stéphanenoblet]

Hi,

The problem of software encoded subtitles and performances is known in the gstreamer community :

Subtitle Overlays and Hardware-Accelerated Playback 

But i don't know if solutions are implemented in NXP gstreamer plugins for IMX

[jack_mao]

IMX8m has no 2D  for composite the subtitle with video , currently it's done by software, so if you decoder a 4k video, more mips consumed by the sw decoding.

[stéphanenoblet]

Hi,

I tryied to play video and render in the GPU with gstreamer glimagesink,

It works on a FullHD video (H.264 1080p), applying GL effects, but doesn't on a UltraHD video (H.265 4K).

Does the I.MX8M GPU can support a 4K stream ?

Or is it not supposed to ?

If no I think the solution to get subtitles working with 4K is to display the 4K video in one DCSS framebuffer and the subtitle in one other framebuffer (using waylandsink).

Stéphane

[joanxie]

refer to the VPU API, imx6 supports up to full HD 1920x1080 60i or 30p decoding and
1920x1088 encoding