# JPEG encoding is not continuous **URL:** \ **Category:** Jetson Nano\ **Tags:** board-design\ **Created:** [October 19, 2022, 12:58am UTC](https://forums.developer.nvidia.com/t/jpeg-encoding-is-not-continuous/231197 "2022-10-19T00:58:27Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![TJCUT](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@TJCUT](https://forums.developer.nvidia.com/u/TJCUT)\ **Post date:** [October 19, 2022, 12:58am UTC](https://forums.developer.nvidia.com/t/jpeg-encoding-is-not-continuous/231197/1 "2022-10-19T00:58:27Z")
Hello Our development environment is as follows: 1. NANO custmize board 2. Jetpack 4.5.1 3. Carmera Input : Pixel format - YUV422, resolution -1920x1080, frame - 30 I am trying to do JPEG encoding using the 12\_camera\_v4l2\_cuda source of Jetson Multimedia api. Jpeg encoding binding source refer to the following. > [@How to convert YUV to JPG using jpeg encoder(hardware)](https://forums.developer.nvidia.com/t/how-to-convert-yuv-to-jpg-using-jpeg-encoder-hardware/47038/9): > > Hi Allen, In the pre-release sample, you can see the camera frame is sent to renderer via Fd: // Render the frame into display if (v4l2\_buf-\>m.planes[0].bytesused) ctx-\>renderer-\>render(buffer-\>planes[0].fd); And you should replace it with the code in 09\_camera\_jpeg\_capture { unsigned long size = JPEG\_BUFFER\_SIZE; unsigned char \*buffer = m\_OutputBuffer; m\_JpegEncoder-\>encodeFromFd(fd, JCS\_YCbCr, &buffer, size); outputFile-\>write((char \*)buffer, siz… The 12\_camera\_v4l2\_cuda sources for combining jpeg encoding refer to the following. > [@How to convert YUV to JPG using jpeg encoder(hardware)](https://forums.developer.nvidia.com/t/how-to-convert-yuv-to-jpg-using-jpeg-encoder-hardware/47038/6): > > Hi Allen, Please follow the steps to complete the JPEG encoding function. 1 Run the command $ gst-launch-1.0 v4l2src device=/dev/video0 num-buffers=300 ! ‘video/x-raw,width=1920,height=1080,format=(string)UYVY’ ! nvvidconv ! ‘video/x-raw(memory:NVMM),format=(string)NV12’ ! nvoverlaysink With output format being set, it should work fine. 2 Try the pre-release sample attached. You should see preview by running $ ./camera\_v4l2\_cuda -d /dev/video0 -s 1920x1080 -f UYVY -n 30 3 Refer to 09\_came… However, JPEG encoding is not continuous as shown below. ```auto -rw-rw-r-- 1 nvidia nvidia 134364 Oct 18 07:34 output001.jpg -rw-rw-r-- 1 nvidia nvidia 0 Oct 18 07:34 output002.jpg -rw-rw-r-- 1 nvidia nvidia 0 Oct 18 07:34 output003.jpg -rw-rw-r-- 1 nvidia nvidia 0 Oct 18 07:34 output004.jpg ``` [camera\_v4l2\_cuda.cpp](https://forums.developer.nvidia.com/uploads/short-url/pvkiq96jGU0izeP9GE3GcHlPHCa.cpp) (24.5 KB) [camera\_v4l2\_cuda.h](https://forums.developer.nvidia.com/uploads/short-url/jI1OxlXQDfaKZtTIdViYdWyKzQM.h) (3.5 KB) Should encoding take care of the synchronization? Is there a function about that? ---
**Author:** ![DaneLLL](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/danelll/32/14043_2.png) [@DaneLLL](https://forums.developer.nvidia.com/u/DaneLLL)\ **Post date:** [October 19, 2022, 1:58am UTC](https://forums.developer.nvidia.com/t/jpeg-encoding-is-not-continuous/231197/3 "2022-10-19T01:58:58Z")
Hi, The patch is for r28 releases. For r32(Jetpack 4) releases, please call _NvBufferTransform()_ to convert YUV422 to I420 and then encode to JPEG. ---
**Author:** ![TJCUT](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@TJCUT](https://forums.developer.nvidia.com/u/TJCUT)\ **Post date:** [October 19, 2022, 8:18am UTC](https://forums.developer.nvidia.com/t/jpeg-encoding-is-not-continuous/231197/4 "2022-10-19T08:18:15Z")
Thank you for your reply. The attached source(r32(Jetpack 4)) does Jpeg encoding after NvBufferTransform(YUV422 to YUV420P). [camera\_v4l2\_cuda.cpp](https://forums.developer.nvidia.com/uploads/short-url/247WrwaaP2GaU7AQWpwIXidFbc4.cpp) (27.0 KB) [camera\_v4l2\_cuda.h](https://forums.developer.nvidia.com/uploads/short-url/eAsFcbfoZT9GIS1zINV7jYMcnds.h) (3.5 KB) ```auto /* Convert the camera buffer from YUV422 to YUV420P */ if (-1 == NvBufferTransform(ctx->g_buff[v4l2_buf.index].dmabuff_fd, ctx->render_dmabuf_fd, &transParams)) ERROR_RETURN("Failed to convert the buffer"); ... /* Preview */ // ctx->renderer->render(ctx->render_dmabuf_fd); write_jpeg(ctx->render_dmabuf_fd, ctx->frame); ``` It’s still not continuous. ```auto -rw-r--r-- 1 nvidia nvidia 123275 Oct 19 08:09 output001.jpg -rw-r--r-- 1 nvidia nvidia 123212 Oct 19 08:09 output002.jpg -rw-r--r-- 1 nvidia nvidia 0 Oct 19 08:09 output003.jpg -rw-r--r-- 1 nvidia nvidia 0 Oct 19 08:09 output004.jpg -rw-r--r-- 1 nvidia nvidia 0 Oct 19 08:09 output005.jpg -rw-r--r-- 1 nvidia nvidia 0 Oct 19 08:09 output006.jpg ``` Is there a way to synchronize it? ---
**Author:** ![DaneLLL](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/danelll/32/14043_2.png) [@DaneLLL](https://forums.developer.nvidia.com/u/DaneLLL)\ **Post date:** [October 20, 2022, 1:56am UTC](https://forums.developer.nvidia.com/t/jpeg-encoding-is-not-continuous/231197/5 "2022-10-20T01:56:01Z")
Hi, Please reset _m\_Size_ to width \* height \* 1.5, after saving the JPEG file, and call next _encodeFromFd()_ ---
**Author:** ![TJCUT](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@TJCUT](https://forums.developer.nvidia.com/u/TJCUT)\ **Post date:** [October 20, 2022, 2:16am UTC](https://forums.developer.nvidia.com/t/jpeg-encoding-is-not-continuous/231197/6 "2022-10-20T02:16:41Z")
Result is the same ```auto // m_Size = (ctx->cam_w * ctx->cam_h) * 3 / 2; m_Size = (ctx->cam_w * ctx->cam_h) * 1.5; ``` ```auto -rw-rw-r-- 1 nvidia nvidia 122665 Oct 20 02:09 output001.jpg -rw-rw-r-- 1 nvidia nvidia 122488 Oct 20 02:09 output002.jpg -rw-rw-r-- 1 nvidia nvidia 0 Oct 20 02:09 output003.jpg -rw-rw-r-- 1 nvidia nvidia 0 Oct 20 02:09 output004.jpg ``` Is there no API waiting for JPEG encoding to finish? ---
**Author:** ![DaneLLL](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/danelll/32/14043_2.png) [@DaneLLL](https://forums.developer.nvidia.com/u/DaneLLL)\ **Post date:** [October 20, 2022, 2:36am UTC](https://forums.developer.nvidia.com/t/jpeg-encoding-is-not-continuous/231197/7 "2022-10-20T02:36:25Z")
Hi, Please new/delete `NvJpegEncoder` in each JPEG encode. The class is demonstrated in 05\_jpeg\_encode sample and as you have tried, it supports single JPEG encoding. ---
**Author:** ![TJCUT](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@TJCUT](https://forums.developer.nvidia.com/u/TJCUT)\ **Post date:** [October 20, 2022, 5:19am UTC](https://forums.developer.nvidia.com/t/jpeg-encoding-is-not-continuous/231197/8 "2022-10-20T05:19:03Z")
Hello, Jpeg encoding was checked normally with the following source. ```auto char filename[256]; sprintf(filename, "output%03u.jpg", (unsigned) frame); std::ofstream *outputFile = new std::ofstream(filename); if (outputFile) { NvJPEGEncoder *jpegEncoder; unsigned char *outputBuffer; unsigned long size = (1920 * 1080) * 1.5; outputBuffer = new unsigned char[size]; unsigned char *buffer = outputBuffer; jpegEncoder = NvJPEGEncoder::createJPEGEncoder("jpenenc"); jpegEncoder->encodeFromFd(dest_dma_fd, JCS_YCbCr, &buffer, size); outputFile->write((char *)buffer, size); delete jpegEncoder; delete outputFile; delete outputBuffer; } else ERROR_RETURN("Failed to initialize camera device"); ``` Thank you for your help. ---
**Author:** ![system](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/system/32/68080_2.png) [@system](https://forums.developer.nvidia.com/u/system)\ **Post date:** [November 9, 2022, 5:18am UTC](https://forums.developer.nvidia.com/t/jpeg-encoding-is-not-continuous/231197/10 "2022-11-09T05:18:13Z")
Closed on November 9, 2022, 5:18am UTC This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.