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PORGB buffer to JPEG buffer, what is wrong here?
 

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  1. PORGB buffer to JPEG buffer, what is wrong here?
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    <p>I need an easy way to convert an buffer containing RGB data into a jpeg. I already tried using libjpeg, but I simply cannot get it to work right. For example, while saving the buffer as a Bitmap produces this:</p> <p><img src="https://i.stack.imgur.com/eVFHx.png" alt="Bitmap Screenshot"></p> <p>Using libjpeg to encode the same image in memory produces this:</p> <p><img src="https://i.stack.imgur.com/QccLg.jpg" alt="enter image description here"></p> <p>And saving the image directly to a file just aborts without giving a warning, error or anything.</p> <p>I certainly need something that works!</p> <p>This is what I am doing</p> <pre><code>void OnKeyPress(unsigned char key, int x, int y) { if (key != static_cast&lt;unsigned char&gt;('p')) return; int width = g_current_width; int height = g_current_height; boost::scoped_array&lt;boost::uint8_t&gt; buffer(new boost::uint8_t[3 * width * height]); glReadBuffer(GL_FRONT); glReadPixels(0, 0, width, height, GL_RGB, GL_UNSIGNED_BYTE, reinterpret_cast&lt;GLvoid *&gt;(buffer.get())); glReadBuffer(GL_BACK); FlipImage(buffer.get(), width, height); // Generate a BMP files for testing purposes SaveRGB("screenshot.bmp", buffer.get(), width, height); jpeg_compress_struct cinfo; jpeg_error_mgr jerr; cinfo.err = jpeg_std_error(&amp;jerr); jerr.trace_level = 10; jpeg_create_compress(&amp;cinfo); boost::uint8_t *jpeg_buffer_raw = NULL; unsigned long outbuffer_size = 0; jpeg_mem_dest(&amp;cinfo, &amp;jpeg_buffer_raw, &amp;outbuffer_size); cinfo.image_width = width; cinfo.image_height = height; cinfo.input_components = 3; cinfo.in_color_space = JCS_RGB; jpeg_set_defaults(&amp;cinfo); jpeg_set_quality(&amp;cinfo, 100, true); jpeg_start_compress(&amp;cinfo, true); int row_stride = width * 3; JSAMPROW row_pointer[1]; int counter = 0; std::cout &lt;&lt; boost::format("height: %d\n") % height; boost::uint8_t *r_buffer = buffer.get(); while (cinfo.next_scanline &lt; cinfo.image_height) { row_pointer[0] = &amp;r_buffer[cinfo.next_scanline * row_stride]; jpeg_write_scanlines(&amp;cinfo, row_pointer, 1); std::cout &lt;&lt; boost::format("current line: %d\n") % (counter++); } jpeg_finish_compress(&amp;cinfo); jpeg_destroy_compress(&amp;cinfo); std::ofstream jpegfile("screenshot.jpg"); jpegfile.write(reinterpret_cast&lt;const char*&gt;(jpeg_buffer_raw), outbuffer_size); jpegfile.flush(); // calling free(jpeg_buffer_raw); or delete[] jpeg_buffer_raw; generates an error } </code></pre>
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    1. PO
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      1. PTAnswer
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    1. USSambatyon
    1. USSambatyon
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    1. This table or related slice is empty.
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      1. PORGB buffer to JPEG buffer, what is wrong here?
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      1. VTUpMod
    2. VO
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      1. PORGB buffer to JPEG buffer, what is wrong here?
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      1. VTUpMod
    1. COHow are you calling libjpeg? Show us the code.
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      1. PORGB buffer to JPEG buffer, what is wrong here?
      1. USThomas
    2. COSO is a question-and-answer site. What is your question?
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      1. PORGB buffer to JPEG buffer, what is wrong here?
      1. USRobᵩ
    3. COSO guys, I update the question with the I am using code.
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      1. PORGB buffer to JPEG buffer, what is wrong here?
      1. USSambatyon
 

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