Libavfilter: Difference between revisions
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Until | Until libavfilter is fully incorporated into [[FFmpeg]], you may get the complete libavfilter source from [[FFmpeg Summer Of Code|GSoC]] SVN repository: | ||
svn checkout svn://svn.mplayerhq.hu/soc/libavfilter | svn checkout svn://svn.mplayerhq.hu/soc/libavfilter | ||
Please read its [http://svn.mplayerhq.hu/soc/libavfilter/README?view=co README] to discover how to integrate | Please read its [http://svn.mplayerhq.hu/soc/libavfilter/README?view=co README] to discover how to integrate libavfilter into ffmpeg and ffplay. | ||
==Reasons why a filter API is needed in FFmpeg== | ==Reasons why a filter API is needed in FFmpeg== |
Revision as of 07:09, 27 March 2008
Until libavfilter is fully incorporated into FFmpeg, you may get the complete libavfilter source from GSoC SVN repository:
svn checkout svn://svn.mplayerhq.hu/soc/libavfilter
Please read its README to discover how to integrate libavfilter into ffmpeg and ffplay.
Reasons why a filter API is needed in FFmpeg
FFmpeg's already well-known libavcodec module has become the de facto standard library for video decoding and encoding in free software projects. Unfortunately, no similar standard library has surfaced for audio/video filtering and otherwise working with audio/video stream once it has been decoded. Various multimedia projects (such as MPlayer, Xine, GStreamer, VirtualDub, etc.) have implemented their own filter systems to various degrees of success. What is needed is a high quality audio and video filter API - efficient, flexible enough to meet all the requirements which have led various projects to invent their own filter system, and yet easy to use or develop new filters with. This proposal is to implement a high quality video API and filter library for FFmpeg, where it can be easily used by other multimedia-related software projects.
Issues that have to be fixed before adding to main tree
- no frame rate estimation is supported (see post in -soc [1])
- a padding filter is lacking (see [2]) -- Updated: vdmsss is working on it
- make ffmpeg.c honor the aspect ratio outputted by the filter chain (thanks vdmsss for the bug report) -- Updated: probably fixed, but maybe not printing the right PAR in the terminal
Feature wish list
Warning: This is not an official wish list. Before implementing any one of these items, ask first in the ffmpeg-devel mailing-list.
- See the TODO file in SoC SVN tree
- Create a SDK (Software Development Kit) with templates for the A/V filter APIs
- Add support for audio filters
- See FFmpeg audio API
- Add support for subtitle filters
- Add a subtitle drawing support to simplify ffplay.c
- Create (or port) additional pre-process and post-process video filters to FFmpeg:
- General post-proc sources are MPlayer (libmpcodecs vf_*.c filters), Xine, FFdshow, VLC, VirtualDub, GStreamer, foobar, and XMMS, vhook
- More image scaling methods:
- SSP (Statistical Post-Processing)
- DeBlocking
- DeRinging
- IVTC
- Sharpen / UnSharpen (Soften)
- ReQuantization
- Auto-Luminance
- Blurring / DeNoising / Spatial Blur / Temporal Blur
- Deinterlace (weave AND bob) filters
- 2:3 pull-down / ivtc (inverse telecine) for 24 progressive-frames on 30 FPS TV's
- NTSC => PAL, and PAL => NTSC frame-rate (FPS) adjust and reclock filter for NTSC <=> PAL conversion
Past discussions on the topic
Threads with previous discussions in the subject:
- Possible adopt MPlayer's A/V filter system or create a new API 'from scratch' for pre-process and post-process audio/video filters:
- See http://article.gmane.org/gmane.comp.video.ffmpeg.devel/39130 for michaelni's idea of what to do.
- Also read this discussion thread on MPlayer's mailing-list:
- See http://article.gmane.org/gmane.comp.video.ffmpeg.devel/39130 for michaelni's idea of what to do.
- Take a look at other existing players API for filter plugins, like for example;
Mentors
A'rpi (has expressed interest of possibly helping with implementing a filter API in FFmpeg, he also volunteering to help porting the MPlayer filters too if a such API becomes available http://lists.mplayerhq.hu/pipermail/mplayer-dev-eng/2007-April/051164.html)