drivers/media/usb/pwc/pwc-uncompress.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* Linux driver for Philips webcam
   3    Decompression frontend.
   4    (C) 1999-2003 Nemosoft Unv.
   5    (C) 2004-2006 Luc Saillard (luc@saillard.org)
   6
   7    NOTE: this version of pwc is an unofficial (modified) release of pwc & pcwx
   8    driver and thus may have bugs that are not present in the original version.
   9    Please send bug reports and support requests to <luc@saillard.org>.
  10    The decompression routines have been implemented by reverse-engineering the
  11    Nemosoft binary pwcx module. Caveat emptor.
  12
  13
  14    vim: set ts=8:
  15 */
  16
  17 #include <asm/current.h>
  18 #include <asm/types.h>
  19
  20 #include "pwc.h"
  21 #include "pwc-dec1.h"
  22 #include "pwc-dec23.h"
  23
  24 int pwc_decompress(struct pwc_device *pdev, struct pwc_frame_buf *fbuf)
  25 {
  26         int n, line, col;
  27         void *yuv, *image;
  28         u16 *src;
  29         u16 *dsty, *dstu, *dstv;
  30
  31         image = vb2_plane_vaddr(&fbuf->vb.vb2_buf, 0);
  32
  33         yuv = fbuf->data + pdev->frame_header_size;  /* Skip header */
  34
  35         /* Raw format; that's easy... */
  36         if (pdev->pixfmt != V4L2_PIX_FMT_YUV420)
  37         {
  38                 struct pwc_raw_frame *raw_frame = image;
  39                 raw_frame->type = cpu_to_le16(pdev->type);
  40                 raw_frame->vbandlength = cpu_to_le16(pdev->vbandlength);
  41                         /* cmd_buf is always 4 bytes, but sometimes, only the
  42                          * first 3 bytes is filled (Nala case). We can
  43                          * determine this using the type of the webcam */
  44                 memcpy(raw_frame->cmd, pdev->cmd_buf, 4);
  45                 memcpy(raw_frame+1, yuv, pdev->frame_size);
  46                 vb2_set_plane_payload(&fbuf->vb.vb2_buf, 0,
  47                         pdev->frame_size + sizeof(struct pwc_raw_frame));
  48                 return 0;
  49         }
  50
  51         vb2_set_plane_payload(&fbuf->vb.vb2_buf, 0,
  52                               pdev->width * pdev->height * 3 / 2);
  53
  54         if (pdev->vbandlength == 0) {
  55                 /* Uncompressed mode.
  56                  *
  57                  * We do some byte shuffling here to go from the
  58                  * native format to YUV420P.
  59                  */
  60                 src = (u16 *)yuv;
  61                 n = pdev->width * pdev->height;
  62                 dsty = (u16 *)(image);
  63                 dstu = (u16 *)(image + n);
  64                 dstv = (u16 *)(image + n + n / 4);
  65
  66                 for (line = 0; line < pdev->height; line++) {
  67                         for (col = 0; col < pdev->width; col += 4) {
  68                                 *dsty++ = *src++;
  69                                 *dsty++ = *src++;
  70                                 if (line & 1)
  71                                         *dstv++ = *src++;
  72                                 else
  73                                         *dstu++ = *src++;
  74                         }
  75                 }
  76
  77                 return 0;
  78         }
  79
  80         /*
  81          * Compressed;
  82          * the decompressor routines will write the data in planar format
  83          * immediately.
  84          */
  85         if (DEVICE_USE_CODEC1(pdev->type)) {
  86
  87                 /* TODO & FIXME */
  88                 PWC_ERROR("This chipset is not supported for now\n");
  89                 return -ENXIO; /* No such device or address: missing decompressor */
  90
  91         } else {
  92                 pwc_dec23_decompress(pdev, yuv, image);
  93         }
  94         return 0;
  95 }