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Avifile Glue for mpeg2_encode by Adam Williams

Note: you are probably looking for news or recent patches/tarballs. The former are to found at the top, right below the toc, the latter at the bottom of this document. Much of the stuff in between has to be considered outdated garbage :-)

Table of Contents

1. Table of Contents
2. About
3. News
4. To Do
5. Improvements
6. References
7. notes
8. Precompiled Binaries antiquated
9. Known Issues
10. Documentation
11. Changelog

About avi2mpegpatch/exportvideo

Coded by Roman Hochleitner (roman at mars tuwien ac at) and Alexander Oelzant-Faderler (alexander at oelzant priv at) with help from Josef Schmid and thanks to Sid (Andreas Varga) for the frames counter and extensive testing against all types of input sources (including .vobs).

This started as a simple patch against Adam Williams' heroinewarrior mpeg2_movie to utilize libavifile by Eugene Smith, however the project got out of hand and currently supports Romans Nuppelvideo file format for input and the MJPEGtools mpeg2enc YUV4MPEG format for output.

Originally this project's intent was not to become a new package, but only to provide the previously missing direct avi->mpeg conversion for the GNU/unix/linux community until the core feature (linking against libaviplay) was integrated into the main encoder, but this goal has been abandoned. We currently hope to enable as many encoders as possible with the avi/nuv/qt-reading functionality.

News

1. since the new toolame-versions (02h or 02i up) don't have the segfaulting bug anymore, there's no need to use psy model 1 anymore
2. Nuppelvideo 0.5 supported from .7e-pre3 up
3. preliminary letterbox-README
4. It seems avi2mpegpatch works fine with libaviplay 0.6 after applying this small patch to aviplugin.C (integrated as a compile time option from 7e-pre1 up), Erik I. Bolsø reports success (small naming/case issues)
5. X11/Xvlib.h and X11/Xv.h can be downloaded since they are the only files needed from the XFree86 4.0 install ... hopefully obsolete soon
6. gzipped the .7. patches which were unzipped but had .gz suffixes
7. READMEs now available
8. We discussed the matter of testfiles. DivX trailers can probably be found all around the net, so we provide a test Nuppelvideo file (SAT1 interactive game show).
9. It seems we finally found the origin of the source we used: Andrew Stevens' encoder that comes with the MJPEGtools is the basis for the current mpeg encoder of the Heroinewarrior project and thus also of the avi/nuv-patched version. There now is a YUVwriter (made out of spare parts from mpeg2_movie) that produces (or at least is supposed to produce, it just got ready) YUV-output suitable for mpeg2enc from the MJPEGtools. exportvideo is a stripped-down version of the mpeg2_movie tree that contains just the files necessary for the exportvideo tool.

10. Dynamic Loading through the glib/gmodule architecture is now experimentally supported, conditional compilation of the nuv/avi parts is configurable, too. Don't worry, the pre-linked version is still the default and works as expected.

11. New: versatile audio extractor for all audio types
    
12. old (more recent patches see above):
    roman made a complete 1.5-version with nuppelvideo for synced recording without framedrops on a <300Mhz K6 (384x288), so everything current is to be found there

    Coming Attractions: scaling/cutting (new, even more recent patch with letterbox generating code against the nuppelvideo enabled encoder from roman) works

To Do

• multi-file support or at least stripping the YUV4MPEG header optionally so the files can be catted in a pipeline like:

  
  (exportvideo file1; (exportvideo file2)|grep -v YUV4MPEG)|mpeg2enc file.m1v                                      
  

• accept threshold (raise to 50!), edge detect as parameters for -D (allow blending instead of proper deinterlacing?)
• Make the audiodecoder write a valid .wav-header (or .voc or ...)
• Adaptive de-interlacing (basically implemented)
• provide test data (see above for .nuv, but I mean "make test"
• use libaviplay-info in audiodecoder (and start toolame automatically?)
• Documentation, manpages
• Synchronisation! - libaviplay certainly returns timestamps, those would have to be evaluated. This is particularly important for files with audio delays at the beginning of the file
  it should also be possible to (sox-)expand audio to the necessary size, but that would only work if video and audio started and ended at the same points of time ... divx often has audio delays at the beginning. This procedure seems unavoidable with respect to quite a few misaligned sound card crystals anyways

Improvements

In addition to the original mpeg2_encode features, the following have been added:

 -D       force deinterlace on (1), off (0), auto (-1, default)
 -S frame#                                      set start frame
 -N frames                       set number of frames to encode
 -G XoutxYout                    scale to this output geometry 
 -g WIDTHxHEIGHT+XOFFxYOFF         scale from this input window
                        (negative numbers produce black borders
                                  - try to use multiples of 16)
 -Y 0|1|2    YUV4MPEG format version: 0 (old, default), 1 (new)
 -a aspectratio                             used with -Y 1 only
 -T timestamptype         set timestamptype (1=time,2=framenum)

A severe bug in the B-frame creation has been worked around which inserted empty frames into mpeg input streams.

References

• Andrew Stevens' MJPEGtools provides the original mpeg2enc, some of which was used in the Heroine project
• Nuppelvideo, the no-drop recording tool for slower (~ >300 MHz) CPUs and larger resolutions, derived from RTJpeg
• The Heroinewarrior project still accounts for much of the framework we wrote our code into
• libavifile and aviplay - hail Eugene Kuznetsov aka Eugene Smith (but use the stable versions)
• sampeg-2/4 by Dirk Farin has similar goals, maybe one day he will integrate libavifile into his encoder (or we might write a YUV4MPEG reader so the existing tools are applicable ...) (freshmeat entry)
• TooLame for fast mpeg 2 encoding (warning: psy model 1 (?) seems to have a segfaulting bug that is triggered every other piece of raw data, workarounds include using ffmpeg, deleting 4 bytes (1 stereo sample) from the input or using psy model 2)

notes

Producing an MPEG 1 or 2 compatible video stream from an asf or avi is easily possible with this patch, however for successful production of a video clip an audio stream and multiplexing will be necessary. libavifile comes with a sample program called extractor which reads 500000 bytes of mp3 from a divx, this patch reads all of it into log2.mp3. Now there is also a real audio decompressor, try the new version here! (binary compiled against 0.53)

caveat: version 2 automatically scales to 44100 Hz stereo 16 bps; upsampling of < 8000 Hz Material doesn't sound particularly good (I ought to get a better grip of the resampling code from sox I adapted for this). At least the annoying problem with 48000 kHz movies most players cannot play should be from the past, the downside is that this version is quite slow due to the algorithm used.

usage:

avifile_audiodecoder infile.avi outfile.raw

or

avifile_audiodecoder infile.avi "|toolame -b 224 -m s - outfile.mp2"

Unfortunately the plethora of debug output from libavifile makes it impossible to use stdout directly.

As for the system stream, to our great astonishment the mplexed system streams grew considerably when we padded them for vcd use. The culprit was the mplex-hi program (-lo didn't sync or even play on most players), which used 2048 instead of 2324 for the sector size. After this minor adjustment vcdpad was content only to pad the very last sector and leave the movie unharmed otherwise.

To remain at least partly compliant with VCD standards (and to play the hires-movies on our humble 166MMX pentia) we decided we had to have B-frames, so we obtained optimum results using settings of -1 -m 2 -q 30 for hires movies and -1 -m 2 -q 10 for lo-res cif tv-series. VBR averaged to about 900 kbps using these settings, which enabled us to produce (overburned) VCDs of movies up to 96 minutes.

According to roman the .ax codecs (responsible for output quality/ postprocessing) should be disabled (move away from /usr/lib/win32). Of course this might influence reencoding quality, so YMMV.

Precompiled Binaries antiquated

avifile_audiodecoder

writes raw audio in whatever samplerate and channel settings the .dll produces, to be fed to toolame or similar

extractor

extracts the undecoded audio stream to a file named "log2.mp3" as is, mostly useful for mp3 divxes (source patch against libavifile/samples/extractor/extractor.cpp)

Known Issues

• fixed?#include <fourcc.h> required (with libavifile 6 only?)
• some compilation problems (encode only compiles with an additional } in mpeg2enc.c)
• fixed mpeg2encode ocassionally hangs at the last frame, utilizing 100 % cpu time without harming the stream any further - fixed in version 2
• fixed (in nuv, too) occasional black frames introduced at avi keyframes? not sure (should be fixed in both dynamic and static versions)

Documentation

• README - basic information much like this page
• README.INSTALL - some installation notes
• README.links - mostly the ascii version of my a/v page
• README.avi2mpeg - a cookbook recipe for transcoding old avi, divx or other libaviplay-compliant streams to VCD (or other) mpeg
• README.bttv2mpeg - like README.avi2mpeg for encoding from a brooktree 848 compatible card to VCD or other mpeg

Changelog

Version 1

• works
• improvements over original mpeg2movie:
  • start frame and number of frames to encode are command line parameters (useful eg for parallel encoding)
  • decodes anything libaviplay can read (currently only if it is in a .asf or .avi-file, since I was too lazy to implement a proper check)
  • produces usable B-frames by buffering frame reads, thus being able to feed the encoder the frame it needs (no-brainer readpic-patch)
  • visible and readable timestamps option for debugging the former

Version 2

• should not hang on last frame any more (stupid while hang)
• mpegs are now seekable (and parallel encodes thus feasible)

Version avi-nuv-scal-dyn (#4)

• As the name suggests, quite a few changes have taken place. The configure-script has been adopted accordingly. Besides there have been a few versions bearing that denomination, (then again previous Nuppelvideo-enabled versions didn't get an entry) so the last one is assigned #4 and the promise is being made not to do it again ;-)
• Nuppelvideo Integration: Roman used the RTJpeg sources, an audio grabber and lots of shared memory to construct a bullet-proof (and most of all pretty framedrop-proof) capturing program which of course has its own output format this tool can read
• MJPEGtools mpeg2enc compatible output: read mpeg (using libmpeg3), quicktime (using Heroinewarrior code), avi (using libaviplay) or Nuppelvideo (rtjpeg-spawned) and encode it using Andrew Stevens' excellent encoder which is far more advanced than Adam Williams' rip off (it actually produces entirely viewable CBR movies ...)
• When I had a night of time I decided it was time to modularize the input system ... now there are compile time options for compiling the nuv-reader or the avi-reader as plugins. Not much sense yet I admit, but maybe it pays off some time (overall code size would most certainly be reduced if I unloaded unused plugins, which I don't (yet) do)
• A scaler has been built in for up/downscaling videos. Since it only interpolates between four pixels, quality will drop if you downscale to less than half the original size.
  This code can handle out-of-bounds offsets so you can introduce letterbox-bars, but be warned it'll be a lot of fiddling ;-)

Version 5

• some small bugs have been fixed (like, say, not being able to decode using libmpeg3 or qt ... :)). There is also an appropriate usage message for exportvideo:

  exportvideo 1.0 (with avi/nuv-patch), 2000/04/04
  (C) 1996, MPEG Software Simulation Group
  (C) 2001 Roman and Alex (+deinterlace +modules)
  Usage: exportvideo [options] <input file> [{outfile.raw|"|encodingprogram"}]
  
  
   -D       force deinterlace on (1), off (0), auto (-1, default)
   -S frame#                                      set start frame
   -N frames                       set number of frames to encode
   -G XoutxYout                    scale to this output geometry 
   -g WIDTHxHEIGHT+XOFFxYOFF         scale from this input window
                          (negative numbers produce black borders
                                    - try to use multiples of 16)
   -T timestamptype         set timestamptype (1=time,2=framenum)
  

  A -Deinterlace option has been added (mainly to turn Romans interlacing code off where it was previously turned on by default)

  The interesting point is the | ... since libaviplay produces too much debug output on stdout, it is impossible to use its stdout, so a pipe hack like the one in avidecoder had to be used.

Version 6 Wed Apr 4 22:38:01 CEST 2001

• More Bugfixes: configure should work now (again), segfault on nuppelvideo (which then again shouldn't produce black frames any more)

Version 7 Thu Apr 5 04:31:30 CEST 2001

• auto-scaling is now (re)enabled, specify a geometry for cutting (-g) and scaling (-G) if this default doesn't suit you
• frame count is correct
• fork waits for kids and should kill them on SIGTERM
• -D for enabling/disabling the deinterlacer roman introduced (actually present since 4, but not announced :))

Version 7b Tue Apr 24 01:55:13 CEST 2001

• } moved outside #ifdef VIDEO_EXPORT_ONLY due to frequent requests
• READMEs finally included with package
• exportvideo should be makeable now (as opposed to being a configure time target)

Version 7c Thu Apr 26 00:08:26 CEST 2001

• made #inclusion of <g*.h> and linking of -lg* dependant upon dynamic compiling (not default), using gtk-config
• configure/Makefile cosmetics (avifile-config)
• IYUV and YV12 seem to produce segfaults instead of Gimages, so they're commented back out for now; YUY2 is used when available, RGBA otherwise :-( (would anyone care to try that out with libaviplay 0.6?)

Version 7e-pre1 Wed May 9 03:03:32 CEST 2001

This is just an interim version (and the attempt to get away from overwriting files again ... it's an addiction ;))

• renamed directories in tgz: mpeg2_movie-1.5-avi-nuv-scal-dyn.version for the full tree and exportvideo.version for the stripped-down package
• removed the annoying framenum: debug message from rtjpeg_input.c ;)
• version is now displayed in usage message
• added a configure-switch for avifile 0.6 support (it seems to work for some people ;)
• replaced mplexhi by romans patched mplexfast version (reads blocks instead of bytes). still not recommended since the MJPEGtools mplex is more versatile
• broke everything ;) by introducing aspect ratio calculations (disabled anyways)
• put linking of -lg* back in since quicktime/libdv seems to need it (why does that compile although I use --no-firewire?) 0.6?)

Version 7e-pre2 Tue May 15 14:11:02 CEST 2001

• moved the return below the declarations in aspectcode.c. sigh.

Version 7e-pre3 Fri Jun 22 04:00:50 CEST 2001

• Nuppelvideo 0.5 support (changed file format)
• preliminary scaling/windowing README

Version 7e-pre4 Don Jul 5 21:35:04 CEST 2001

• Nuppelvideo 0.52a support (changed file format)

Version 7e-pre5 Tue Aug 28 20:35:30 CEST 2001

• included avifile_audiodecoder .02, which now scales to 44100 Hz/16 bit/stereo using the resampling algorithm from sox

Version 7e-pre6 Thu Oct 4 06:21:17 CEST 2001

• YUV4MPEG new format supported
• display aspect ratio (for former) can be passed on the commandline
• new toolame copied to audiomp2 directory (might go away altogether)
• binary package included (with all libraries: a pita to download, but runnable everywhere when setting LD_LIBRARY_PATH to the .bin.-directory)

Version 7e-pre7 Thu Oct 4 17:15:37 CEST 2001

• display aspect ratio switch -a now produces correct A header element (for new YUV4MPEG output)

Version 7e-pre8 Tue Oct 9 16:29:16 CEST 2001

• dynamic-loading version doesn't have stdout-garbage-bug any more (closing stdout at the right point helped ...) (configure with --dynamic --codec-dir=`pwd`/video/codecs or install codecs in /usr/lib/mpeg2_movie/codecs after compilation)
• sed-oneliner for concatenating files included
• nuv2mpeg-script in contrib (thanks to Leandro Lucarella (luca at lucarella dot com dot ar))

Version 7e-pre9 Fri Oct 26 03:35:27 CEST 2001

• yet another YUV4MPEG format (YUV4MPEG2), aspect code now prudently omitted when 1:1 display aspect ratio seems the only possible guess (interlace/progressive info omitted too, no point in inventing nonsense)
• Downloads:
  • Patch against previous version
  • Patch against Romans current Nuppelvideo source tree
  • Patch against mpeg2_movie 1.5 by Adam Williams
  • complete tarball
  • tarball containing only the exportvideo (aka YUV4MPEG writer apt for encoding with the MJPEGtools mpeg2enc
  • new:binary tarball including all libraries (LD_LIBRARY_PATH=. ./exportvideo* should run everywhere)

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