[Ffmpeg-devel] [PATCH] Auto-resize ffplay video

Steven Sheehy steven.sheehy
Sun Dec 31 02:44:29 CET 2006

Michael Niedermayer wrote:
> Hi
> On Fri, Dec 29, 2006 at 05:07:14PM -0600, Steven Sheehy wrote:
>> Michael Niedermayer wrote:
>>> Hi
>>> On Tue, Dec 26, 2006 at 03:12:38PM -0600, Steven Sheehy wrote:
>>>> On Sat, Dec 23, 2006 at 15:20:36 CET 2006, Michael Niedermayer wrote:
>>>>> seperate issue seperate patch please
>>>> I could've characterized this patch more generically by saying it 
>>>> resolves the improper resizing of the video window, if you prefer. In 
>>>> addition, if I were to make them separate they would still depend on each 
>>>> other since the patch to auto-resize the output modifies text before the 
>>>> exiting from full screen bug. Nevertheless, here's the patch for just 
>>>> this issue:
>>> [mangled unuseable patch]
>>>>> screen_width / screen_height should either be set to the dimensions of
>>>>> the video or should be at 0 by default and then be overridden by
>>>>> the video w/h if they are 0 where used
>>>> I've tried this, but I've found that if you pass a width and height of 0 
>>>> to the initial SDL_SetVideoMode(), it causes the video window to be 
>>>> maximized and future SDL_SetVideoMode()'s to be ignored (SDL bug?). 
>>>> screen_width / screen_height cannot be set to the video dimensions at 
>>>> declaration time or in main() since they can only be determined at a much 
>>>> later point in the program when alloc_picture() is called. If have any 
>>>> suggestions to overcome these issues, I'd be grateful.
>>> what about calling SDL_SetVideoMode() after av_find_stream_info() ?
>> I followed your advice and basically moved the initial call to 
>> SDL_SetVideoMode() from main() to decode_thread() after 
>> av_find_stream_info(). This works perfectly for me, but I'm not sure if 
>> this is how you want it. Let me know if I need to tweak it more.
> hmm, maybe putting the code into stream_component_open() would be better
> sample_rate for audio is also set there, so w/h seems to fit pretty well
> also stream_cycle_channel() calls stream_component_open() and if the
> w/h changes should update the window size
> of course the code could also be put into its own function which would
> then be called by stream_component_open() ...
> [...]

I see you decided just to write your own solution.

In testing your approach, I've discovered some bugs:

* Crashes when playing non-video files
* Crashes if I specify a negative value for -x option (it is better to check if 
(screen_width <= 0) instead of just if (screen_width)).
* When -y option is specified by itself it is ignored.
* When -x option is specified by itself the height is not the default height of 
the video.
* Returning from full-screen ignores any resizing the user did.

As I found out and you can probably see, this resizing issue is a bit more 
troublesome than it at first seems. :)

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