[FFmpeg-devel] [PATCH 13/17] lavc/mjpeg: Add profiles for MJPEG using SOF marker codes

[Mark Thompson]

On 24/11/17 11:27, Carl Eugen Hoyos wrote:
> 2017-11-24 1:51 GMT+01:00 Mark Thompson <sw at jkqxz.net>:
>> This is needed by later hwaccel code to tell which encoding process was
>> used for a particular frame, because hardware decoders may only support a
>> subset of possible methods.
>> ---
>>  libavcodec/avcodec.h  | 6 ++++++
>>  libavcodec/mjpegdec.c | 7 +++++++
>>  2 files changed, 13 insertions(+)
>>
>> diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
>> index 0972df0bde..c1e68b1d13 100644
>> --- a/libavcodec/avcodec.h
>> +++ b/libavcodec/avcodec.h
>> @@ -2897,6 +2897,12 @@ typedef struct AVCodecContext {
>>  #define FF_PROFILE_HEVC_MAIN_STILL_PICTURE          3
>>  #define FF_PROFILE_HEVC_REXT                        4
>>
>> +#define FF_PROFILE_MJPEG_HUFFMAN_BASELINE_DCT            0xc0
>> +#define FF_PROFILE_MJPEG_HUFFMAN_EXTENDED_SEQUENTIAL_DCT 0xc1
>> +#define FF_PROFILE_MJPEG_HUFFMAN_PROGRESSIVE_DCT         0xc2
>> +#define FF_PROFILE_MJPEG_HUFFMAN_LOSSLESS                0xc3
>> +#define FF_PROFILE_MJPEG_JPEG_LS                         0xf7
> 
> Sorry if I misread the code:
> If you (thankfully) define these as in the specification, why don't you
> simply set them without the "if()"'s?

They have to be set inside the switch because there are other non-SOF markers there.

In each case they could then be set from start_code, but it seemed clearer to write the profile out properly?

I can change it to use start_code directly if you prefer.

- Mark