kevin thayer <nufan_wfk@xxxxxxxxx> writes:
> B) Request lots of additions to the spec, and wait for
> the v4l gurus to hash out a standard
> C) something else.
Go ahead building something for the v4l2 API. I've recently fixed up
some minor v4l2 API issues (diff below). The (currently unused)
struct v4l2_compression and related ioctls can be recycled for the
MPEG settings. I've added a long comment assembled from mails on this
list there.
As there are _lots_ of settings for MPEG1/2 it is probably a good idea to
split the whole thing into some groups. Maybe this way:
struct v4l2_compression { /* rename to mpeg_compression ??? */
unsigned int group;
union {
struct system { ... };
struct video { ... };
struct audio { ... };
};
};
Semantics of the S_COMP should be consistent with the other v4l2 S_*
ioctls, i.e. the driver is allowed to change the parameters to match
the hardware capabilities and the application has to check returned
parameters to see if they fit the needs.
Gerd
==============================[ cut here ]==============================
diff -ur -X /home/kraxel/.kdontdiff linux-2003-03-15.orig/drivers/media/video/videodev.c linux-2003-03-15/drivers/media/video/videodev.c
--- linux-2003-03-15.orig/drivers/media/video/videodev.c 2003-03-17 12:37:37.833156664 +0100
+++ linux-2003-03-15/drivers/media/video/videodev.c 2003-03-17 12:32:51.000000000 +0100
@@ -121,6 +121,15 @@
void *parg = NULL;
int err = -EINVAL;
+ /* for compatibility, will go away some day */
+ switch (cmd) {
+ case VIDIOC_OVERLAY_OLD: cmd = VIDIOC_OVERLAY; break;
+ case VIDIOC_S_PARM_OLD: cmd = VIDIOC_S_PARM; break;
+ case VIDIOC_S_CTRL_OLD: cmd = VIDIOC_S_CTRL; break;
+ case VIDIOC_G_AUDIO_OLD: cmd = VIDIOC_G_AUDIO; break;
+ case VIDIOC_G_AUDOUT_OLD: cmd = VIDIOC_G_AUDOUT; break;
+ }
+
/* Copy arguments into temp kernel buffer */
switch (_IOC_DIR(cmd)) {
case _IOC_NONE:
diff -ur -X /home/kraxel/.kdontdiff linux-2003-03-15.orig/include/linux/videodev2.h linux-2003-03-15/include/linux/videodev2.h
--- linux-2003-03-15.orig/include/linux/videodev2.h 2003-03-17 12:38:21.411531744 +0100
+++ linux-2003-03-15/include/linux/videodev2.h 2003-03-17 13:00:46.860992336 +0100
@@ -13,7 +13,9 @@
* Justin Schoeman
* et al.
*/
+#ifdef __KERNEL__
#include <linux/time.h> /* need struct timeval */
+#endif
/*
* M I S C E L L A N E O U S
@@ -144,8 +146,9 @@
#define V4L2_CAP_VBI_OUTPUT 0x00000020 /* Is a VBI output device */
#define V4L2_CAP_RDS_CAPTURE 0x00000100 /* RDS data capture */
-#define V4L2_CAP_TUNER 0x00010000 /* Has a tuner */
+#define V4L2_CAP_TUNER 0x00010000 /* has a tuner */
#define V4L2_CAP_AUDIO 0x00020000 /* has audio support */
+#define V4L2_CAP_RADIO 0x00040000 /* is a radio device */
#define V4L2_CAP_READWRITE 0x01000000 /* read/write systemcalls */
#define V4L2_CAP_ASYNCIO 0x02000000 /* async I/O */
@@ -264,6 +267,51 @@
__u32 keyframerate;
__u32 pframerate;
__u32 reserved[5];
+
+/* what we'll need for MPEG, extracted from some postings on
+ the v4l list (Gert Vervoort, PlasmaJohn).
+
+system stream:
+ - type: elementary stream(ES), packatised elementary stream(s) (PES)
+ program stream(PS), transport stream(TS)
+ - system bitrate
+ - PS packet size (DVD: 2048 bytes, VCD: 2324 bytes)
+ - TS video PID
+ - TS audio PID
+ - TS PCR PID
+ - TS system information tables (PAT, PMT, CAT, NIT and SIT)
+ - (MPEG-1 systems stream vs. MPEG-2 program stream (TS not supported
+ by MPEG-1 systems)
+
+audio:
+ - type: MPEG (+Layer I,II,III), AC-3, LPCM
+ - bitrate
+ - sampling frequency (DVD: 48 Khz, VCD: 44.1 KHz, 32 kHz)
+ - Trick Modes? (ff, rew)
+ - Copyright
+ - Inverse Telecine
+
+video:
+ - picturesize (SIF, 1/2 D1, 2/3 D1, D1) and PAL/NTSC norm can be set
+ through excisting V4L2 controls
+ - noise reduction, parameters encoder specific?
+ - MPEG video version: MPEG-1, MPEG-2
+ - GOP (Group Of Pictures) definition:
+ - N: number of frames per GOP
+ - M: distance between reference (I,P) frames
+ - open/closed GOP
+ - quantiser matrix: inter Q matrix (64 bytes) and intra Q matrix (64 bytes)
+ - quantiser scale: linear or logarithmic
+ - scanning: alternate or zigzag
+ - bitrate mode: CBR (constant bitrate) or VBR (variable bitrate).
+ - target video bitrate for CBR
+ - target video bitrate for VBR
+ - maximum video bitrate for VBR - min. quantiser value for VBR
+ - max. quantiser value for VBR
+ - adaptive quantisation value
+ - return the number of bytes per GOP or bitrate for bitrate monitoring
+
+*/
};
#endif
@@ -783,22 +831,22 @@
#define VIDIOC_QUERYBUF _IOWR ('V', 9, struct v4l2_buffer)
#define VIDIOC_G_FBUF _IOR ('V', 10, struct v4l2_framebuffer)
#define VIDIOC_S_FBUF _IOW ('V', 11, struct v4l2_framebuffer)
-#define VIDIOC_OVERLAY _IOWR ('V', 14, int)
+#define VIDIOC_OVERLAY _IOW ('V', 14, int)
#define VIDIOC_QBUF _IOWR ('V', 15, struct v4l2_buffer)
#define VIDIOC_DQBUF _IOWR ('V', 17, struct v4l2_buffer)
#define VIDIOC_STREAMON _IOW ('V', 18, int)
#define VIDIOC_STREAMOFF _IOW ('V', 19, int)
#define VIDIOC_G_PARM _IOWR ('V', 21, struct v4l2_streamparm)
-#define VIDIOC_S_PARM _IOW ('V', 22, struct v4l2_streamparm)
+#define VIDIOC_S_PARM _IOWR ('V', 22, struct v4l2_streamparm)
#define VIDIOC_G_STD _IOR ('V', 23, v4l2_std_id)
#define VIDIOC_S_STD _IOW ('V', 24, v4l2_std_id)
#define VIDIOC_ENUMSTD _IOWR ('V', 25, struct v4l2_standard)
#define VIDIOC_ENUMINPUT _IOWR ('V', 26, struct v4l2_input)
#define VIDIOC_G_CTRL _IOWR ('V', 27, struct v4l2_control)
-#define VIDIOC_S_CTRL _IOW ('V', 28, struct v4l2_control)
+#define VIDIOC_S_CTRL _IOWR ('V', 28, struct v4l2_control)
#define VIDIOC_G_TUNER _IOWR ('V', 29, struct v4l2_tuner)
#define VIDIOC_S_TUNER _IOW ('V', 30, struct v4l2_tuner)
-#define VIDIOC_G_AUDIO _IOWR ('V', 33, struct v4l2_audio)
+#define VIDIOC_G_AUDIO _IOR ('V', 33, struct v4l2_audio)
#define VIDIOC_S_AUDIO _IOW ('V', 34, struct v4l2_audio)
#define VIDIOC_QUERYCTRL _IOWR ('V', 36, struct v4l2_queryctrl)
#define VIDIOC_QUERYMENU _IOWR ('V', 37, struct v4l2_querymenu)
@@ -807,7 +855,7 @@
#define VIDIOC_G_OUTPUT _IOR ('V', 46, int)
#define VIDIOC_S_OUTPUT _IOWR ('V', 47, int)
#define VIDIOC_ENUMOUTPUT _IOWR ('V', 48, struct v4l2_output)
-#define VIDIOC_G_AUDOUT _IOWR ('V', 49, struct v4l2_audioout)
+#define VIDIOC_G_AUDOUT _IOR ('V', 49, struct v4l2_audioout)
#define VIDIOC_S_AUDOUT _IOW ('V', 50, struct v4l2_audioout)
#define VIDIOC_G_MODULATOR _IOWR ('V', 54, struct v4l2_modulator)
#define VIDIOC_S_MODULATOR _IOW ('V', 55, struct v4l2_modulator)
@@ -820,6 +868,15 @@
#define VIDIOC_S_JPEGCOMP _IOW ('V', 62, struct v4l2_jpegcompression)
#define VIDIOC_QUERYSTD _IOR ('V', 63, v4l2_std_id)
#define VIDIOC_TRY_FMT _IOWR ('V', 64, struct v4l2_format)
+#define VIDIOC_ENUMAUDIO _IOWR ('V', 65, struct v4l2_audio)
+#define VIDIOC_ENUMAUDOUT _IOWR ('V', 66, struct v4l2_audioout)
+
+/* for compatibility, will go away some day */
+#define VIDIOC_OVERLAY_OLD _IOWR ('V', 14, int)
+#define VIDIOC_S_PARM_OLD _IOW ('V', 22, struct v4l2_streamparm)
+#define VIDIOC_S_CTRL_OLD _IOW ('V', 28, struct v4l2_control)
+#define VIDIOC_G_AUDIO_OLD _IOWR ('V', 33, struct v4l2_audio)
+#define VIDIOC_G_AUDOUT_OLD _IOWR ('V', 49, struct v4l2_audioout)
#define BASE_VIDIOC_PRIVATE 192 /* 192-255 are private */
