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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-10-20 00:10:27 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-10-20 00:10:27 -0300
commitd0b2f91bede3bd5e3d24dd6803e56eee959c1797 (patch)
tree7fee4ab0509879c373c4f2cbd5b8a5be5b4041ee /drivers/media/usb/usbtv/usbtv-video.c
parente914f8eb445e8f74b00303c19c2ffceaedd16a05 (diff)
Linux-libre 4.8.2-gnupck-4.8.2-gnu
Diffstat (limited to 'drivers/media/usb/usbtv/usbtv-video.c')
-rw-r--r--drivers/media/usb/usbtv/usbtv-video.c61
1 files changed, 45 insertions, 16 deletions
diff --git a/drivers/media/usb/usbtv/usbtv-video.c b/drivers/media/usb/usbtv/usbtv-video.c
index f6cfad465..2a089756c 100644
--- a/drivers/media/usb/usbtv/usbtv-video.c
+++ b/drivers/media/usb/usbtv/usbtv-video.c
@@ -1,19 +1,6 @@
/*
- * Fushicai USBTV007 Audio-Video Grabber Driver
- *
- * Product web site:
- * http://www.fushicai.com/products_detail/&productId=d05449ee-b690-42f9-a661-aa7353894bed.html
- *
- * Following LWN articles were very useful in construction of this driver:
- * Video4Linux2 API series: http://lwn.net/Articles/203924/
- * videobuf2 API explanation: http://lwn.net/Articles/447435/
- * Thanks go to Jonathan Corbet for providing this quality documentation.
- * He is awesome.
- *
* Copyright (c) 2013 Lubomir Rintel
* All rights reserved.
- * No physical hardware was harmed running Windows during the
- * reverse-engineering activity
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -26,6 +13,33 @@
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL").
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+/*
+ * Fushicai USBTV007 Audio-Video Grabber Driver
+ *
+ * Product web site:
+ * http://www.fushicai.com/products_detail/&productId=d05449ee-b690-42f9-a661-aa7353894bed.html
+ *
+ * Following LWN articles were very useful in construction of this driver:
+ * Video4Linux2 API series: http://lwn.net/Articles/203924/
+ * videobuf2 API explanation: http://lwn.net/Articles/447435/
+ * Thanks go to Jonathan Corbet for providing this quality documentation.
+ * He is awesome.
+ *
+ * No physical hardware was harmed running Windows during the
+ * reverse-engineering activity
*/
#include <media/v4l2-ioctl.h>
@@ -251,8 +265,23 @@ static int usbtv_setup_capture(struct usbtv *usbtv)
/* Copy data from chunk into a frame buffer, deinterlacing the data
* into every second line. Unfortunately, they don't align nicely into
* 720 pixel lines, as the chunk is 240 words long, which is 480 pixels.
- * Therefore, we break down the chunk into two halves before copyting,
- * so that we can interleave a line if needed. */
+ * Therefore, we break down the chunk into two halves before copying,
+ * so that we can interleave a line if needed.
+ *
+ * Each "chunk" is 240 words; a word in this context equals 4 bytes.
+ * Image format is YUYV/YUV 4:2:2, consisting of Y Cr Y Cb, defining two
+ * pixels, the Cr and Cb shared between the two pixels, but each having
+ * separate Y values. Thus, the 240 words equal 480 pixels. It therefore,
+ * takes 1.5 chunks to make a 720 pixel-wide line for the frame.
+ * The image is interlaced, so there is a "scan" of odd lines, followed
+ * by "scan" of even numbered lines.
+ *
+ * Following code is writing the chunks in correct sequence, skipping
+ * the rows based on "odd" value.
+ * line 1: chunk[0][ 0..479] chunk[0][480..959] chunk[1][ 0..479]
+ * line 3: chunk[1][480..959] chunk[2][ 0..479] chunk[2][480..959]
+ * ...etc.
+ */
static void usbtv_chunk_to_vbuf(u32 *frame, __be32 *src, int chunk_no, int odd)
{
int half;
@@ -608,7 +637,7 @@ static struct v4l2_file_operations usbtv_fops = {
static int usbtv_queue_setup(struct vb2_queue *vq,
unsigned int *nbuffers,
- unsigned int *nplanes, unsigned int sizes[], void *alloc_ctxs[])
+ unsigned int *nplanes, unsigned int sizes[], struct device *alloc_devs[])
{
struct usbtv *usbtv = vb2_get_drv_priv(vq);
unsigned size = USBTV_CHUNK * usbtv->n_chunks * 2 * sizeof(u32);