Hi James,
> On Oct 18, 2016, at 11:20 PM, James Almer <jamr...@gmail.com> wrote:
>
> Signed-off-by: James Almer <jamr...@gmail.com>
> ---
> libavformat/matroskaenc.c | 6 ++++--
> tests/fate/matroska.mak | 2 +-
> 2 files changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c
> index 6f2957c..03d5326 100644
> --- a/libavformat/matroskaenc.c
> +++ b/libavformat/matroskaenc.c
> @@ -1192,8 +1192,10 @@ static int mkv_write_track(AVFormatContext *s,
> MatroskaMuxContext *mkv,
> av_log(s, AV_LOG_ERROR, "Overflow in display width\n");
> return AVERROR(EINVAL);
> }
> - put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , d_width /
> display_width_div);
> - put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, par->height /
> display_height_div);
> + if (d_width != par->width || display_width_div != 1 ||
> display_height_div != 1) {
> + put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , d_width /
> display_width_div);
> + put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT,
> par->height / display_height_div);
> + }
> } else if (display_width_div != 1 || display_height_div != 1) {
> put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , par->width /
> display_width_div);
> put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, par->height /
> display_height_div);
You could also make the storage simpler by considering whether or not to write
DisplayWidth and DisplayHeight independently. For instance:
PixelWidth=720
PixelHeight=480
DisplayWidth=640
DisplayHeight=480
could be simplified to this (as DisplayHeight if unstored, defaults to
PixelHeight)
PixelWidth=720
PixelHeight=480
DisplayWidth=640
However I'm worried that this may break things when #4489 and/or #5301 are
resolved. As the DisplayWidth/Height are intended to be used after cropping. In
the attached example on #5301 it has:
PixelWidth=320
PixelHeight=240
PixelCropBottom=40
PixelCropTop=0
PixelCropLeft=240
PixelCropRight=40
DisplayWidth=320
DisplayHeight=240
If this was remuxed with your patch AND a potential patch to pass PixelCrop
elements from source mkv to output mkv, then the result would be:
PixelWidth=320
PixelHeight=240
PixelCropBottom=40
PixelCropTop=0
PixelCropLeft=240
PixelCropRight=40
and since the Display Elements are not stored, they would be evaluated as
DisplayWidth as "PixelWidth - PixelCropLeft - PixelCropRight"
DisplayHeight = "PixelHeight - PixelCropTop - PixelCropBottom"
which is
DisplayWidth=40
DisplayHeight=200
which is wrong, since the original file intended to show the cropped 40x200
image in a 320x240 display.
Dave Rice
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