Problems with JPEG decoder Xavier Jetpack Version: 5.1.1-b56

[ddrell]

in the multi-media sample NvJPegDecoder::decodeToBuffer() or NvJPegDecoder::decodeToFd(), am getting a pixelformat V4L2_PIX_FMT_YUV422RM. I cannot find a definition of this anywhere or how to decode it. Looking a the Nppi primitives for color-space conversion and I cannot find a corresponding function.

Also, if I use decodeToFd(), the resulting fd == -1.

[DaneLLL]

Hi,
The supported formats of hardware JPEG decoder are listed in
Log in | NVIDIA Developer

Not sure which format your JPEG file is. Please attach it and we can check whether it is supported or not.

[ddrell]

here are some jpegs I have been using for my tests.

[DaneLLL]

Hi,
We can decode the images successfully by running 06_jpeg_decode sample. Decoded YUVs are in YUV420 and you can check it by running:

$ gst-launch-1.0 filesrc location= ~/a.yuv ! videoparse format=2 width=1920 height=1080 ! imagefreeze ! xvimagesink

Resolution of the images is different so please change width and height to fit the image.

[ddrell]

hi,
how is g-streamer related to the nvidia 06-jpeg-decode sample?
thank you.

[ddrell]

I find if I use the program jetson_multimedia_api/samples/06_jpeg_decode, that decodeToFd() does work, but decodeToBuffer() does not work. For example, this works:

./jpeg_decode num_files 1 /media/samsung/TimeLapseImager/src/tli/3rdParty/MImage/test/resources/jpeg/256x256_color.jpg /media/samsung/TimeLapseImager/src/tli/3rdParty/MImage/test/resources/jpeg/256x256_color.yuv

If I open the yuv file using YUVView, I see this:

But if I use decodeToBuffer(), as follows:
./jpeg_decode num_files 1 /media/samsung/TimeLapseImager/src/tli/3rdParty/MImage/test/resources/jpeg/256x256_color.jpg /media/samsung/TimeLapseImager/src/tli/3rdParty/MImage/test/resources/jpeg/256x256_color.yuv --decode-buffer

I see this in YUVView:

[ddrell]

I found a case that does not work with both decodeToBuffer() and decodeToFd(), using the samples/06 program.

./jpeg_decode num_files 1 img_000000000_10x_brightlight_266.jpg img_000000000_10x_brightlight_266.yuv

Then the resulting yuv file looks like this in YUV:

[ddrell]

as you can see, the scale is off.

[DaneLLL]

Hi,
Certain files may fail to be decoded in calling decodeToFd and please call decodeToBuffer() in the case.

If you use nvjpegdec plugin in gstreamer, the gst-jpeg package is open source and you can take a look to check further.