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 #include <asm/current.h>
  15 #include <asm/types.h>
  16
  17 #include "pwc.h"
  18 #include "pwc-dec1.h"
  19 #include "pwc-dec23.h"
  20
  21 int pwc_decompress(struct pwc_device *pdev, struct pwc_frame_buf *fbuf)
  22 {
  23         int n, line, col;
  24         void *yuv, *image;
  25         u16 *src;
  26         u16 *dsty, *dstu, *dstv;
  27
  28         image = vb2_plane_vaddr(&fbuf->vb.vb2_buf, 0);
  29
  30         yuv = fbuf->data + pdev->frame_header_size;  /* Skip header */
  31
  32         /* Raw format; that's easy... */
  33         if (pdev->pixfmt != V4L2_PIX_FMT_YUV420)
  34         {
  35                 struct pwc_raw_frame *raw_frame = image;
  36                 raw_frame->type = cpu_to_le16(pdev->type);
  37                 raw_frame->vbandlength = cpu_to_le16(pdev->vbandlength);
  38                         /* cmd_buf is always 4 bytes, but sometimes, only the
  39                          * first 3 bytes is filled (Nala case). We can
  40                          * determine this using the type of the webcam */
  41                 memcpy(raw_frame->cmd, pdev->cmd_buf, 4);
  42                 memcpy(raw_frame->rawframe, yuv, pdev->frame_size);
  43                 vb2_set_plane_payload(&fbuf->vb.vb2_buf, 0,
  44                         struct_size(raw_frame, rawframe, pdev->frame_size));
  45                 return 0;
  46         }
  47
  48         vb2_set_plane_payload(&fbuf->vb.vb2_buf, 0,
  49                               pdev->width * pdev->height * 3 / 2);
  50
  51         if (pdev->vbandlength == 0) {
  52                 /* Uncompressed mode.
  53                  *
  54                  * We do some byte shuffling here to go from the
  55                  * native format to YUV420P.
  56                  */
  57                 src = (u16 *)yuv;
  58                 n = pdev->width * pdev->height;
  59                 dsty = (u16 *)(image);
  60                 dstu = (u16 *)(image + n);
  61                 dstv = (u16 *)(image + n + n / 4);
  62
  63                 for (line = 0; line < pdev->height; line++) {
  64                         for (col = 0; col < pdev->width; col += 4) {
  65                                 *dsty++ = *src++;
  66                                 *dsty++ = *src++;
  67                                 if (line & 1)
  68                                         *dstv++ = *src++;
  69                                 else
  70                                         *dstu++ = *src++;
  71                         }
  72                 }
  73
  74                 return 0;
  75         }
  76
  77         /*
  78          * Compressed;
  79          * the decompressor routines will write the data in planar format
  80          * immediately.
  81          */
  82         if (DEVICE_USE_CODEC1(pdev->type)) {
  83
  84                 /* TODO & FIXME */
  85                 PWC_ERROR("This chipset is not supported for now\n");
  86                 return -ENXIO; /* No such device or address: missing decompressor */
  87
  88         } else {
  89                 pwc_dec23_decompress(pdev, yuv, image);
  90         }
  91         return 0;
  92 }