Comment by gus_massa | Hacker News Reader

Comment by gus_massa | Hacker News Reader

I don't like how they interpret the table with the numbers of commits.

I tried this criteria, I divide the committers in three groups:

A) Michael Niedermayer

B) People with more commits in FFmpeg, i.e. Clément Bœsch, James Almer Carl, Eugen Hoyos, ...

C) People with more commits in libav, i.e. Vittorio Giovara, Martin Storsjö, Anton Khirnov, ...

(I supouse there are other commits from people outside the published table, but they are few.)

Statistics:

        libav  FFmpeg
  A)       46    1831
  B)       37    1071
  C)     1074     856
  Tot:   1157   3758

An alternative interpretation is that if tomorrow Michael Niedermayer is hit by a bus, the other committers of FFmpeg still make almost the same numbers of commits than the committers of libav (even ignoring the ported commits).

Complete table:

  Developer           libav   FFmpeg
  ---------------------------------   
  Michael Niedermayer    46    1831
  ---------------------------------   
  Clément Bœsch                 179
  James Almer                   155
  Carl Eugen Hoyos              150
  Andreas Cadhalpun      21     114
  Lukasz Marek                   98
  Paul B Mahol                   93
  Ronald S. Bultje               85
  wm4                    16      83
  Christophe Gisquet             66
  Benoit Fouet                   48
  >>>Subtotal            37    1071
  ---------------------------------
  Vittorio Giovara      294     294
  Martin Storsjö        253     252
  Anton Khirnov         206     197
  Luca Barbato          131     113
  Diego Biurrun          72 
  Rémi Denis-Courmont    32 
  Hendrik Leppkes        17 
  Himangi Saraogi        16 
  Gabriel Dume           16 
  Federico Tomassetti    14 
  Peter Meerwald         12 
  Janne Grunau           11 
  >>>Subtotal          1074     856
  ------------------------------------
  >>>>>>Total          1157    3758

As you can see many of the other major contributors to ffmpeg are also contributors to libav. This is explained that ffmpeg merges back a lot of libav but not so much in the other direction. In other words, if this is true and all major contributors except for Michael are in fact libav developers then ffmpeg might have a hard time when Michael leaves.

But since Michael alone seems to "outdevelop" all others, ffmpeg comes ahead in terms of features and supported codecs, so people prefer ffmpeg. Since i don't know the ffmpeg APIs or the code quality, i don't know if it is true that ffmpeg has the worse design and development process. If it is true and Michael leaves it sounds like a lot work to take over. On the other hand... i understand that libav was already a fork of ffmpeg.. So some people did take over the code in the past.

Just restating what the article says.

Perhaps the table is not clear enought. I don't know about the exact members of each group, so I have to guess. I hope nobody get offended if misclassified.

Let's put Michael Niedermayer in his own group "A".

Clément Bœsch has no commits in libav and 179 in FFmpeg. So I guess he's in the FFmpeg team.

Andreas Cadhalpun has 21 in libav and 114 in FFmpeg . So I guess he's in the FFmpeg team.

I put all the persons who have more commits in FFmpeg than in libav in the FFmpeg team. Let's call this team "B". The classification is clear, because in all the cases the difference is big.

Vittorio Giovara has 294 commits in libav and 294 in FFmpeg. It's a tie! It's more difficult to guess, but I put him in the libav team. (This choice makes the bus factor bigger.)

Martin Storsjö has 253 in libav and 252 in FFmpeg. It's also difficult to guess, but I put him in the libav team.

I put all the persons who have more commits in libav in FFmpeg in the libav team. Let's call this team "C". Some cases are difficult to classify, but I choose the classification that makes the bus factor bigger.

In the table:

        libav  FFmpeg
  A)       46    1831
  B)       37    1071
  C)     1074     856
  Tot:   1157   3758

Ignoring the group A) and making a lot of assumptions, the table it can be read as

The persons in group B wrote 1071 commits for FFmpeg and 37 of them were copied to libav

The persons in group C wrote 1074 commits for libav and 856 of them were copied to FFmpeg.

The moral is that with the data of the table it's not clear that the group B is much smaller than group C. Only that group A is bigger than both!

My guess that Michael is (in git terms) committer, not patch author. Would be interesting to see table for authors.

Good point. It's quite difficult to assign authorship automatically. Take a look at this not-yet-merged commit: https://git.allseenalliance.org/gerrit/#/c/4870/ who authored it? Todd. Who has signed off on editing it? Todd and me. How would you assign ownership? By LOC, Todd wrote essentially 100% of the patch, but since I edited it last, my name is last in the list of editors.

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