[rtcweb] Trellis IPR status? (Re: H261/MPEG-1 video quality)

Harald Alvestrand <harald@alvestrand.no> Tue, 19 November 2013 08:00 UTC

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Date: Tue, 19 Nov 2013 09:00:31 +0100
From: Harald Alvestrand <harald@alvestrand.no>
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Subject: [rtcweb] Trellis IPR status? (Re: H261/MPEG-1 video quality)
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On 11/16/2013 02:22 PM, Maik Merten wrote:
> I filed the ffmpeg bug regarding H.261. In a nutshell: ffmpeg
> currently crashes when enabling a certain encoder feature which turns
> out to be very useful for other codecs ("trellis quantization" - which
> basically means that coefficients to be coded are selected with the
> encoding costs in mind) for the H.261 encoder. This is a rather new
> encoder feature which pays of very nicely for other formats and should
> be applicable for H.261 as well.

Just checking: Do you know the patent status of trellis quantization?

One issue this particular WG has with codecs is that in order to have a
non-IPR-encumbered spec, we need a non-IPR-encumbered encoder too -
unlike the situation for playback-only contexts, where a
non-IPR-encumbered decoder may be enough.

Thus, people who describe a particular quality level achievable with a
non-IPR-encumbered codec would seem to have to describe a
non-IPR-encumbered encoder that can achieve that quality level, too.