<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <meta name="Generator" content="Microsoft Word 14 (filtered medium)"> <base href="https://bugs.freedesktop.org/"><style></style> </head> <body lang="ZH-CN" link="blue" vlink="purple"> <div class="WordSection1"> found another issue: in gstreamer-codec-parser, not all case we get the converted scanning order , please review the following code in “gst-libs/gst/codecparsers/gstmpegvideoparser.c”, If no matrix contained in bitstream, default zig-zag matrix will be loaded. In two case , we get different types of order.<o:p></o:p> <o:p> </o:p> gst-libs/gst/codecparsers/gstmpegvideoparser.c<o:p></o:p> /* default intra quant matrix, in zig-zag order */<o:p></o:p> static const guint8 default_intra_quantizer_matrix[64] = {<o:p></o:p> 8,<o:p></o:p> 16, 16,<o:p></o:p> 19, 16, 19,<o:p></o:p> 22, 22, 22, 22,<o:p></o:p> 22, 22, 26, 24, 26,<o:p></o:p> 27, 27, 27, 26, 26, 26,<o:p></o:p> 26, 27, 27, 27, 29, 29, 29,<o:p></o:p> 34, 34, 34, 29, 29, 29, 27, 27,<o:p></o:p> 29, 29, 32, 32, 34, 34, 37,<o:p></o:p> 38, 37, 35, 35, 34, 35,<o:p></o:p> 38, 38, 40, 40, 40,<o:p></o:p> 48, 48, 46, 46,<o:p></o:p> 56, 56, 58,<o:p></o:p> 69, 69,<o:p></o:p> 83<o:p></o:p> };<o:p></o:p> <o:p> </o:p> /* load_intra_quantiser_matrix */<o:p></o:p> READ_UINT8 (&br, load_intra_flag, 1);<o:p></o:p> if (load_intra_flag) {<o:p></o:p> gint i;<o:p></o:p> for (i = 0; i < 64; i++)<o:p></o:p> READ_UINT8 (&br, seqhdr->intra_quantizer_matrix[mpeg_zigzag_8x8[i]], 8); //case 1. Here seqhdr->intra_quantizer_matrix is filled with scan order matrix<o:p></o:p> } else<o:p></o:p> memcpy (seqhdr->intra_quantizer_matrix, default_intra_quantizer_matrix, 64); //case 2. Here seqhdr->intra_quantizer_matrix is filled with zig-zaged order matrix<o:p></o:p> <o:p> </o:p> <o:p> </o:p> <o:p> </o:p> Thanks,<o:p></o:p> Xiaowei<o:p></o:p> <o:p> </o:p> <div> <div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm"> From: Li, Jocelyn Sent: Thursday, January 31, 2013 12:28 PM To: Yuan, Feng; Beauchesne, Gwenole; Xiang, Haihao; Li, Xiaowei A Cc: Zhao, Halley; Zhong, CongX; <a href="mailto:libva@lists.freedesktop.org"> libva@lists.freedesktop.org</a> Subject: RE: [Bug 58176] [gst-vaapi] gi4_video.bits decoding failed (MPEG2)<o:p></o:p> </div> </div> <o:p> </o:p> Added Xiaowei.<o:p></o:p> <o:p> </o:p> <div> <div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm"> From: Yuan, Feng Sent: Thursday, January 31, 2013 11:09 AM To: Li, Jocelyn; Beauchesne, Gwenole; Xiang, Haihao Cc: Zhao, Halley; Zhong, CongX; <a href="mailto:libva@lists.freedesktop.org"> libva@lists.freedesktop.org</a> Subject: RE: [Bug 58176] [gst-vaapi] gi4_video.bits decoding failed (MPEG2)<o:p></o:p> </div> </div> <o:p> </o:p> Copy to libva maillist, it’s more about gstreamer-codec-parser/gst-vaapi/libva/driver related issues.<o:p></o:p> <o:p> </o:p> Hi all,<o:p></o:p> It’s an issue about how to process the zigzagged quantization table between gstreamer level and driver level.<o:p></o:p> Libva defined API of <o:p></o:p> typedef struct _VAIQMatrixBufferMPEG2<o:p></o:p> {<o:p></o:p> int load_intra_quantiser_matrix;<o:p></o:p> int load_non_intra_quantiser_matrix;<o:p></o:p> int load_chroma_intra_quantiser_matrix;<o:p></o:p> int load_chroma_non_intra_quantiser_matrix;<o:p></o:p> unsigned char intra_quantiser_matrix[64];<o:p></o:p> unsigned char non_intra_quantiser_matrix[64];<o:p></o:p> unsigned char chroma_intra_quantiser_matrix[64];<o:p></o:p> unsigned char chroma_non_intra_quantiser_matrix[64];<o:p></o:p> } VAIQMatrixBufferMPEG2;<o:p></o:p> Question is how to fill <xxx_intra_quantiser_matrix>, is it zigzag ordered or scan ordered? Mpeg2 data store the quantization table in zigzag order. Currently gstreamer-codec-parser would parse all zigzagged quantization table from MPEG2 data and converting into scanning order. Intel-Driver would do the same thing again. The result certainly would be incorrect.<o:p></o:p> Ffmpeg would fill the quantiser_matrix by zigzag order, do we need to change gstreamer-codec-parse to read data into zigzag order? Does any other package/lib already using gstreamer-codec-parser(mpeg2)? Which package should be the right role to do the conversion from zigzag to scanning order?<o:p></o:p> <o:p> </o:p> Thanks,<o:p></o:p> Wind<o:p></o:p> <o:p> </o:p> </div> </body> </html>