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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-28 00:58:31 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-28 00:58:31 +0300 |
commit | ff9a082fda424257976f08fce942609f358015e0 (patch) | |
tree | 478e6b449b19baaf842369a13923499ce83ef895 /Documentation/video4linux/cx2341x/README.hm12 | |
parent | 6a492b0f23d28e1f946cdf08e54617484400dafb (diff) | |
parent | 85538b1ad145c67198cb55d02de14ba269cc323d (diff) | |
download | linux-ff9a082fda424257976f08fce942609f358015e0.tar.xz |
Merge tag 'media/v4.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media documentation updates from Mauro Carvalho Chehab:
"This patch series does the conversion of all media documentation stuff
to Restrutured Text markup format and add them to the
Documentation/index.rst file.
The media documentation was grouped into 4 books:
- media uAPI
- media kAPI
- V4L driver-specific documentation
- DVB driver-specific documentation
It also contains several documentation improvements and one fixup
patch for a core issue with cropcap.
PS. After this patch series, the media DocBook is deprecated and
should be removed. I'll add such patch on a future pull request"
* tag 'media/v4.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (322 commits)
[media] cx23885-cardlist.rst: add a new card
[media] doc-rst: add some needed escape codes
[media] doc-rst: kapi: use :c:func: instead of :cpp:func
doc-rst: kernel-doc: fix a change introduced by mistake
[media] v4l2-ioctl.h add debug info for struct v4l2_ioctl_ops
[media] dvb_ringbuffer.h: some documentation improvements
[media] v4l2-ctrls.h: fully document the header file
[media] doc-rst: Fix some typedef ugly warnings
[media] doc-rst: reorganize the kAPI v4l2 chapters
[media] rename v4l2-framework.rst to v4l2-intro.rst
[media] move V4L2 clocks to a separate .rst file
[media] v4l2-fh.rst: add cross references and markups
[media] v4l2-fh.rst: add fh contents from v4l2-framework.rst
[media] v4l2-fh.h: add documentation for it
[media] v4l2-event.rst: add cross-references and markups
[media] v4l2-event.h: document all functions
[media] v4l2-event.rst: add text from v4l2-framework.rst
[media] v4l2-framework.rst: remove videobuf quick chapter
[media] v4l2-dev: add cross-references and improve markup
[media] doc-rst: move v4l2-dev doc to a separate file
...
Diffstat (limited to 'Documentation/video4linux/cx2341x/README.hm12')
-rw-r--r-- | Documentation/video4linux/cx2341x/README.hm12 | 120 |
1 files changed, 0 insertions, 120 deletions
diff --git a/Documentation/video4linux/cx2341x/README.hm12 b/Documentation/video4linux/cx2341x/README.hm12 deleted file mode 100644 index b36148ea0750..000000000000 --- a/Documentation/video4linux/cx2341x/README.hm12 +++ /dev/null @@ -1,120 +0,0 @@ -The cx23416 can produce (and the cx23415 can also read) raw YUV output. The -format of a YUV frame is specific to this chip and is called HM12. 'HM' stands -for 'Hauppauge Macroblock', which is a misnomer as 'Conexant Macroblock' would -be more accurate. - -The format is YUV 4:2:0 which uses 1 Y byte per pixel and 1 U and V byte per -four pixels. - -The data is encoded as two macroblock planes, the first containing the Y -values, the second containing UV macroblocks. - -The Y plane is divided into blocks of 16x16 pixels from left to right -and from top to bottom. Each block is transmitted in turn, line-by-line. - -So the first 16 bytes are the first line of the top-left block, the -second 16 bytes are the second line of the top-left block, etc. After -transmitting this block the first line of the block on the right to the -first block is transmitted, etc. - -The UV plane is divided into blocks of 16x8 UV values going from left -to right, top to bottom. Each block is transmitted in turn, line-by-line. - -So the first 16 bytes are the first line of the top-left block and -contain 8 UV value pairs (16 bytes in total). The second 16 bytes are the -second line of 8 UV pairs of the top-left block, etc. After transmitting -this block the first line of the block on the right to the first block is -transmitted, etc. - -The code below is given as an example on how to convert HM12 to separate -Y, U and V planes. This code assumes frames of 720x576 (PAL) pixels. - -The width of a frame is always 720 pixels, regardless of the actual specified -width. - -If the height is not a multiple of 32 lines, then the captured video is -missing macroblocks at the end and is unusable. So the height must be a -multiple of 32. - --------------------------------------------------------------------------- - -#include <stdio.h> -#include <stdlib.h> -#include <string.h> - -static unsigned char frame[576*720*3/2]; -static unsigned char framey[576*720]; -static unsigned char frameu[576*720 / 4]; -static unsigned char framev[576*720 / 4]; - -static void de_macro_y(unsigned char* dst, unsigned char *src, int dstride, int w, int h) -{ - unsigned int y, x, i; - - // descramble Y plane - // dstride = 720 = w - // The Y plane is divided into blocks of 16x16 pixels - // Each block in transmitted in turn, line-by-line. - for (y = 0; y < h; y += 16) { - for (x = 0; x < w; x += 16) { - for (i = 0; i < 16; i++) { - memcpy(dst + x + (y + i) * dstride, src, 16); - src += 16; - } - } - } -} - -static void de_macro_uv(unsigned char *dstu, unsigned char *dstv, unsigned char *src, int dstride, int w, int h) -{ - unsigned int y, x, i; - - // descramble U/V plane - // dstride = 720 / 2 = w - // The U/V values are interlaced (UVUV...). - // Again, the UV plane is divided into blocks of 16x16 UV values. - // Each block in transmitted in turn, line-by-line. - for (y = 0; y < h; y += 16) { - for (x = 0; x < w; x += 8) { - for (i = 0; i < 16; i++) { - int idx = x + (y + i) * dstride; - - dstu[idx+0] = src[0]; dstv[idx+0] = src[1]; - dstu[idx+1] = src[2]; dstv[idx+1] = src[3]; - dstu[idx+2] = src[4]; dstv[idx+2] = src[5]; - dstu[idx+3] = src[6]; dstv[idx+3] = src[7]; - dstu[idx+4] = src[8]; dstv[idx+4] = src[9]; - dstu[idx+5] = src[10]; dstv[idx+5] = src[11]; - dstu[idx+6] = src[12]; dstv[idx+6] = src[13]; - dstu[idx+7] = src[14]; dstv[idx+7] = src[15]; - src += 16; - } - } - } -} - -/*************************************************************************/ -int main(int argc, char **argv) -{ - FILE *fin; - int i; - - if (argc == 1) fin = stdin; - else fin = fopen(argv[1], "r"); - - if (fin == NULL) { - fprintf(stderr, "cannot open input\n"); - exit(-1); - } - while (fread(frame, sizeof(frame), 1, fin) == 1) { - de_macro_y(framey, frame, 720, 720, 576); - de_macro_uv(frameu, framev, frame + 720 * 576, 720 / 2, 720 / 2, 576 / 2); - fwrite(framey, sizeof(framey), 1, stdout); - fwrite(framev, sizeof(framev), 1, stdout); - fwrite(frameu, sizeof(frameu), 1, stdout); - } - fclose(fin); - return 0; -} - --------------------------------------------------------------------------- |