[FFmpeg-devel] [PATCH] avformat/avidec: ensure that palette does not contain the BottomUp info.

[Michael Niedermayer]

On Tue, Sep 23, 2014 at 03:11:58PM +0200, Michael Niedermayer wrote:
> On Tue, Sep 23, 2014 at 01:33:30PM +0200, Benoit Fouet wrote:
> > Hi,
> > 
> > ----- Mail original -----
> > > Hi,
> > > 
> > > ----- Mail original -----
> > > > On Tue, Sep 23, 2014 at 10:19:17AM +0200, Benoit Fouet wrote:
> > > 
> > > > > Here is a patch to illustrate this...
> > > > 
> > > > this looks better but:
> > > > 
> > > > 
> > > > [...]
> > > > > -                ff_put_bmp_header(pb, enc, ff_codec_bmp_tags, 0,
> > > > > 0);
> > > > > +                if (keep_height) {
> > > > > +                    enc->extradata_size -= 9;
> > > > > +                    if (!enc->extradata_size)
> > > > > +                        av_freep(&enc->extradata);
> > > > > +                }
> > > > 
> > > > what if extradata is stored in 2 files, the 2nd muxer would no
> > > > longer
> > > > see it
> > > > also the muxer shouldnt change the encoders/demuxer extradata
> > > > 
> > > > and cant all this logic be put in ff_put_bmp_header() ?
> > > > might even be simpler
> > > > 
> > > 
> > > Do you mean that ff_put_bmp_header() would check for the BottomUp
> > > presence and not negate height in this case, and also only write the
> > > palette in the stream?
> > > 
> > 
> > Patch attached, just in case this is what you meant...
> 
> >  riffenc.c |    6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> > d3a93efc5680ad2340086a61ba3d59749f67e770  0001-avformat-riffenc-extend-ff_put_bmp_header-to-be-able.patch
> > From b8c8f07555769215af7a10c48e7a479f783a7c49 Mon Sep 17 00:00:00 2001
> > From: Benoit Fouet <benoit.fouet at free.fr>
> > Date: Tue, 23 Sep 2014 10:07:10 +0200
> > Subject: [PATCH] avformat/riffenc: extend ff_put_bmp_header to be able to
> >  force height to not be changed.
> > 
> > When stream copying, height shouldn't be changed when writing the
> > BITMAPINFOHEADER header if the BottomUp information is present in the
> > extradata.
> > ---
> >  libavformat/riffenc.c | 6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> > 
> > diff --git a/libavformat/riffenc.c b/libavformat/riffenc.c
> > index ef4d399..f1a2274 100644
> > --- a/libavformat/riffenc.c
> > +++ b/libavformat/riffenc.c
> > @@ -209,11 +209,13 @@ int ff_put_wav_header(AVIOContext *pb, AVCodecContext *enc, int flags)
> >  void ff_put_bmp_header(AVIOContext *pb, AVCodecContext *enc,
> >                         const AVCodecTag *tags, int for_asf, int ignore_extradata)
> >  {
> > +    int keep_height = enc->extradata_size >= 9 &&
> > +                      !memcmp(enc->extradata + enc->extradata_size - 9, "BottomUp", 9);
> >      /* size */
> >      avio_wl32(pb, 40 + (ignore_extradata ? 0 : enc->extradata_size));
> >      avio_wl32(pb, enc->width);
> >      //We always store RGB TopDown
> > -    avio_wl32(pb, enc->codec_tag ? enc->height : -enc->height);
> > +    avio_wl32(pb, enc->codec_tag || keep_height ? enc->height : -enc->height);
> >      /* planes */
> >      avio_wl16(pb, 1);
> >      /* depth */
> 
> > @@ -227,7 +229,7 @@ void ff_put_bmp_header(AVIOContext *pb, AVCodecContext *enc,
> >      avio_wl32(pb, 0);
> >  
> >      if (!ignore_extradata) {
> > -        avio_write(pb, enc->extradata, enc->extradata_size);
> > +        avio_write(pb, enc->extradata, keep_height ? enc->extradata_size : enc->extradata_size - 9);
> 
> this corrupts the stored extradata and breaks fate

fixed and applied

thanks

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Those who are best at talking, realize last or never when they are wrong.
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