linux/drivers/media/video/pwc/pwc-misc.c
Hans de Goede 885fe18f55 [media] pwc: Replace private buffer management code with videobuf2
Looking at the pwc buffer management code has made it clear to me it needed
some serious fixing. Not only was there a ton of code duplication even
internally to pwc (read and mmap wait for frame code was duplicated), the
code also was outright buggy. With the worst offender being dqbuf, which
just round robin returned all the mmap buffers, without paying any attention
to them being queued by the app with qbuf or not. And qbuf itself was a noop.

So I set out to fix this and already had some cleanups in place when
I read Jonathan Corbet's lwn article on videobuf2, this inspired me to just
rip out the buffer management code and replace it with videobuf2, greatly
reducing the amount of code, and fixing all bugs in one go:

Many thanks to Jonathan for the timely article on this !

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2011-07-27 17:53:43 -03:00

130 lines
3.9 KiB
C

/* Linux driver for Philips webcam
Various miscellaneous functions and tables.
(C) 1999-2003 Nemosoft Unv.
(C) 2004-2006 Luc Saillard (luc@saillard.org)
NOTE: this version of pwc is an unofficial (modified) release of pwc & pcwx
driver and thus may have bugs that are not present in the original version.
Please send bug reports and support requests to <luc@saillard.org>.
The decompression routines have been implemented by reverse-engineering the
Nemosoft binary pwcx module. Caveat emptor.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "pwc.h"
const struct pwc_coord pwc_image_sizes[PSZ_MAX] =
{
{ 128, 96, 0 }, /* sqcif */
{ 160, 120, 0 }, /* qsif */
{ 176, 144, 0 }, /* qcif */
{ 320, 240, 0 }, /* sif */
{ 352, 288, 0 }, /* cif */
{ 640, 480, 0 }, /* vga */
};
/* x,y -> PSZ_ */
int pwc_decode_size(struct pwc_device *pdev, int width, int height)
{
int i, find;
/* Make sure we don't go beyond our max size.
NB: we have different limits for RAW and normal modes. In case
you don't have the decompressor loaded or use RAW mode,
the maximum viewable size is smaller.
*/
if (pdev->pixfmt != V4L2_PIX_FMT_YUV420)
{
if (width > pdev->abs_max.x || height > pdev->abs_max.y)
{
PWC_DEBUG_SIZE("VIDEO_PALETTE_RAW: going beyond abs_max.\n");
return -1;
}
}
else
{
if (width > pdev->view_max.x || height > pdev->view_max.y)
{
PWC_DEBUG_SIZE("VIDEO_PALETTE_not RAW: going beyond view_max.\n");
return -1;
}
}
/* Find the largest size supported by the camera that fits into the
requested size.
*/
find = -1;
for (i = 0; i < PSZ_MAX; i++) {
if (pdev->image_mask & (1 << i)) {
if (pwc_image_sizes[i].x <= width && pwc_image_sizes[i].y <= height)
find = i;
}
}
return find;
}
/* initialize variables depending on type and decompressor*/
void pwc_construct(struct pwc_device *pdev)
{
if (DEVICE_USE_CODEC1(pdev->type)) {
pdev->view_min.x = 128;
pdev->view_min.y = 96;
pdev->view_max.x = 352;
pdev->view_max.y = 288;
pdev->abs_max.x = 352;
pdev->abs_max.y = 288;
pdev->image_mask = 1 << PSZ_SQCIF | 1 << PSZ_QCIF | 1 << PSZ_CIF;
pdev->vcinterface = 2;
pdev->vendpoint = 4;
pdev->frame_header_size = 0;
pdev->frame_trailer_size = 0;
} else if (DEVICE_USE_CODEC3(pdev->type)) {
pdev->view_min.x = 160;
pdev->view_min.y = 120;
pdev->view_max.x = 640;
pdev->view_max.y = 480;
pdev->image_mask = 1 << PSZ_QSIF | 1 << PSZ_SIF | 1 << PSZ_VGA;
pdev->abs_max.x = 640;
pdev->abs_max.y = 480;
pdev->vcinterface = 3;
pdev->vendpoint = 5;
pdev->frame_header_size = TOUCAM_HEADER_SIZE;
pdev->frame_trailer_size = TOUCAM_TRAILER_SIZE;
} else /* if (DEVICE_USE_CODEC2(pdev->type)) */ {
pdev->view_min.x = 128;
pdev->view_min.y = 96;
/* Anthill bug #38: PWC always reports max size, even without PWCX */
pdev->view_max.x = 640;
pdev->view_max.y = 480;
pdev->image_mask = 1 << PSZ_SQCIF | 1 << PSZ_QSIF | 1 << PSZ_QCIF | 1 << PSZ_SIF | 1 << PSZ_CIF | 1 << PSZ_VGA;
pdev->abs_max.x = 640;
pdev->abs_max.y = 480;
pdev->vcinterface = 3;
pdev->vendpoint = 4;
pdev->frame_header_size = 0;
pdev->frame_trailer_size = 0;
}
pdev->pixfmt = V4L2_PIX_FMT_YUV420; /* default */
pdev->view_min.size = pdev->view_min.x * pdev->view_min.y;
pdev->view_max.size = pdev->view_max.x * pdev->view_max.y;
}