[FFmpeg-devel] [PATCH 1/3] decklink: add fourCC of display mode to list_format output

[Marton Balint]

On Thu, 16 Mar 2017, Matthias Hunstock wrote:

> Am 16.03.2017 um 20:55 schrieb Marton Balint:
>> 
>> 
>> On Thu, 16 Mar 2017, Matthias Hunstock wrote:
>> 
>>> ---
>>> libavdevice/decklink_common.cpp | 11 +++++++----
>>> 1 file changed, 7 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/libavdevice/decklink_common.cpp
>>> b/libavdevice/decklink_common.cpp
>>> index 8b499c5..131d186 100644
>>> --- a/libavdevice/decklink_common.cpp
>>> +++ b/libavdevice/decklink_common.cpp
>>> @@ -276,6 +276,7 @@ int ff_decklink_list_formats(AVFormatContext
>>> *avctx, decklink_direction_t direct
>>>     struct decklink_ctx *ctx = (struct decklink_ctx *)cctx->ctx;
>>>     IDeckLinkDisplayModeIterator *itermode;
>>>     IDeckLinkDisplayMode *mode;
>>> +    char fourcc[32];
>>>     int i=0;
>>>     HRESULT res;
>>>
>>> @@ -297,13 +298,15 @@ int ff_decklink_list_formats(AVFormatContext
>>> *avctx, decklink_direction_t direct
>>>             return AVERROR(EIO);
>>>     }
>>>
>>> -    av_log(avctx, AV_LOG_INFO, "Supported formats for '%s':\n",
>>> +    av_log(avctx, AV_LOG_INFO, "Supported formats for
>>> '%s':\n\tmode\tfourCC\tdescription",
>>>                avctx->filename);
>>>     while (itermode->Next(&mode) == S_OK) {
>>>         BMDTimeValue tb_num, tb_den;
>>>         mode->GetFrameRate(&tb_num, &tb_den);
>>> -        av_log(avctx, AV_LOG_INFO, "\t%d\t%ldx%ld at %d/%d fps",
>>> -                ++i,mode->GetWidth(), mode->GetHeight(),
>>> +        av_get_codec_tag_string(fourcc, sizeof(fourcc),
>>> mode->GetDisplayMode());
>>> +        av_log(avctx, AV_LOG_INFO, "\n\t%d\t%c%c%c%c\t%ldx%ld at
>>> %d/%d fps",
>>> +                ++i, fourcc[3], fourcc[2], fourcc[1], fourcc[0],
>>> +                mode->GetWidth(), mode->GetHeight(),
>> 
>> fourcc is a string, is there a reason why you don't simply print it
>> using "%s"?
>
> Yes, unfortunately the order is reversed then, and I considered 'cstn'
> or '05iH' harder to remember and use than 'ntsc' or 'Hi50'. Did not find
> any util function that does the fourCC conversion in that reverse order.
>

Oh, I see. Maybe you can use av_bswap32 to transform the BMDDisplayMode to 
the proper byte order before transfroming it to fourcc string.

Regards,
Marton