Review Request: Remove FFmpeg dependencies from the new MusicBrainz fingerprinting by using Phonon::AudioDataOutput instead of FFmpeg directly

[Kevin Kofler]

> On 2010-10-04 13:30:31, Daniel Dewald wrote:
> >
> 
> Daniel Dewald wrote:
>     This is far from being complete. It something of a beginning. I just basically removes the ffmpeg stuff but puts nothing into place to replace it. A slot for the audioDataReady signal is created but not implemented anywhere let alone being connected somehow to some audioDataOutput. This has to go a long way before it could work. Also remember that the audioDataOutput was originally invented for visualizing stuff.. so the data wont come in at once.. you'd have to build some kind of buffer (as I did) before this could work. otherwise musicbrainz will either hang or starve.

> I just basically removes the ffmpeg stuff but puts nothing into place to replace it.

Uh yes, it puts a Phonon::AudioDataOutput in place.

> A slot for the audioDataReady signal is created but not implemented anywhere

line 160:
void MusicDNSAudioDecoder::handleFrame(const QMap<Phonon::AudioDataOutput::Channel, QVector<qint16> > &data)

> let alone being connected somehow to some audioDataOutput.

lines 130-131:
    connect(&dataout, SIGNAL(dataReady(const QMap<Phonon::AudioDataOutput::Channel, QVector<qint16> >&)),
            this,  SLOT(handleFrame(const QMap<Phonon::AudioDataOutput::Channel,    QVector<qint16> >&)));

> you'd have to build some kind of buffer (as I did) before this could work.

The DecodedAudioData class in the original FFmpeg-based code is already such a buffer. FFmpeg doesn't deliver all the data at once either, the code used a loop. Due to how Phonon::AudioDataOutput works, I replaced the loop with a QThread event loop.


- Kevin


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On 2010-10-03 23:07:03, Kevin Kofler wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> http://git.reviewboard.kde.org/r/100021/
> -----------------------------------------------------------
> 
> (Updated 2010-10-03 23:07:03)
> 
> 
> Review request for amarok.
> 
> 
> Summary
> -------
> 
> This patch removes FFmpeg dependencies from the new MusicBrainz fingerprinting by using Phonon::AudioDataOutput instead of FFmpeg directly.
> 
> WARNING: This version of the patch is completely untested and may not even build.
> In addition, Phonon::AudioDataOutput may not be ready for production use yet (crashes, decoding speed issues).
> You have been warned.
> 
> 
> Diffs
> -----
> 
>   CMakeLists.txt baacef5 
>   src/musicbrainz/MusicDNSAudioDecoder.h 97976f6 
>   src/musicbrainz/MusicDNSAudioDecoder.cpp eef459a 
> 
> Diff: http://git.reviewboard.kde.org/r/100021/diff
> 
> 
> Testing
> -------
> 
> None yet.
> 
> 
> Thanks,
> 
> Kevin
> 
>

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