[Mplayer-dvb] future plans

[Arpi]

Hi,

> How about Mpeg4->Mpeg2 or Mpeg4->Mpeg1 transcoding i.e. partial decoding the
> divx stream? Are there any simularities in MpegX video decompression that might
> be used to speed up things?

I've wrote about this earlier in details.
Yes, the basic idea of mpeg 1,2 4 are the same: DCT and motion compensation.
the coding differs, but it's the smaller part of decoding/coding, so in
theory it's possible to transcode.

but divx variants and other h263-like stuff uses so-called unrestricted MC,
it means the coded/decoded image is bigger than visible part. there is a 32
pixel width border around the image, composed by pixels of image corners.
i think it's possible to implement, but it requires heavy modifications of
the firmware, and as we have no source nor docs of it, it's near impossible.
i'm also not sure about the SAA chip even supports different coded and
displayed size. (watching the thin ugly flickering border around the video
is not an option imho)


A'rpi / Astral & ESP-team

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mailto:arpi at thot.banki.hu
http://esp-team.scene.hu