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+1, yuv, pdev->frame_size); 43 vb2_set_plane_payload(&fbuf->vb.vb2_buf, 0, 44 pdev->frame_size + sizeof(struct pwc_raw_frame)); 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 } 93