[FFmpeg-devel] [GSoC] Patch which add simple P frame support for ffv1

[Yingming Fan]

I will continue working on this.

Firstly, i will fix crash and make sure everything OK without P frame.

Then, i will add some optimization that select between intra and inter to
decrease bitstream size.

Best regards.

2015-04-24 0:36 GMT+08:00 Michael Niedermayer <michaelni at gmx.at>:

> On Fri, Apr 24, 2015 at 12:03:38AM +0800, Yingming Fan wrote:
> > Hi, everyone.
> >
> > This is my GSoC qualification task, add simple P frame for ffv1.
> >
> > P frame will work when you add -level 4.
> >
> > eg. ffmpeg -pix_fmt yuv420p -s xxxx -i xx.yuv -vcodec ffv1 -level 4
> test.nut
> >
> > Notice: Only support yuv colorspace and 8 bit currently, i will support
> > these in later time.
> >
> > Other option about ffv1 can be find here:
> > http://trac.ffmpeg.org/wiki/Encode/FFV1
> >
> > About test.
> >
> > I haven't send FATE result to server as i'm not that familiar with those
> > staff. But i will complete this as soon as possible.
> >
> > Best regards
>
> >  ffv1.c    |   10 +++++++
> >  ffv1.h    |    1
> >  ffv1dec.c |   54 +++++++++++++++++++++++++++++---------
> >  ffv1enc.c |   87
> ++++++++++++++++++++++++++++++++++++++++++++++++++------------
> >  4 files changed, 124 insertions(+), 28 deletions(-)
> > 56a6b95f90706b65b833f1a359c08f927fdc1124
> 0001-Add-simple-P-frame-support-for-ffv1.patch
> > From 5fcc87093ce1f2aea3a43b52399b09fdf8acda36 Mon Sep 17 00:00:00 2001
> > From: Yingming Fan <yingmingfan at gmail.com>
> > Date: Thu, 23 Apr 2015 23:19:05 +0800
> > Subject: [PATCH] Add simple P frame support for ffv1.
>
> breaks ffv1 with normal intra frames:
> ./ffmpeg -i matrixbench_mpeg2.mpg -vf format=gbrp10 -vcodec ffv1 -t 1
> test.avi
> just segfaults
>
> ./ffmpeg   -i matrixbench_mpeg2.mpg  -vcodec ffv1 -level 3 -t 1 test-3.nut
> ./ffmpeg   -i matrixbench_mpeg2.mpg  -vcodec ffv1 -level 4 -t 1 test-4.nut
>
> -rw-r----- 1 michael michael 2325508 Apr 23 18:24 test-3.nut
> -rw-r----- 1 michael michael 3394282 Apr 23 18:24 test-4.nut
>
> the file with P frames is 50% bigger, thats not a good start,
> considering the goal is to improve compression of the currently
> existing FFV1
>
> [...]
>
> --
> Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
> Asymptotically faster algorithms should always be preferred if you have
> asymptotical amounts of data
>
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