[patch] v4l2 api: mpeg encoder support

From: Gerd Knorr
Date: Tue Mar 08 2005 - 06:29:06 EST


Add a ioctl to set mpeg hardware encoder parameters.

Signed-off-by: Gerd Knorr <kraxel@xxxxxxxxxxx>
---
include/linux/videodev2.h | 136 ++++++++++++++++++++++----------------
1 files changed, 82 insertions(+), 54 deletions(-)

Index: linux-2.6.11-rc4/include/linux/videodev2.h
===================================================================
--- linux-2.6.11-rc4.orig/include/linux/videodev2.h 2005-02-14 15:24:05.000000000 +0100
+++ linux-2.6.11-rc4/include/linux/videodev2.h 2005-02-15 12:37:28.000000000 +0100
@@ -268,64 +268,92 @@ struct v4l2_timecode
/* The above is based on SMPTE timecodes */


+#if 1
/*
- * C O M P R E S S I O N P A R A M E T E R S
+ * M P E G C O M P R E S S I O N P A R A M E T E R S
+ *
+ * ### WARNING: this is still work-in-progress right now, most likely
+ * ### there will be some incompatible changes.
+ *
*/
-#if 0
-/* ### generic compression settings don't work, there is too much
- * ### codec-specific stuff. Maybe reuse that for MPEG codec settings
- * ### later ... */
-struct v4l2_compression
-{
- __u32 quality;
- __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)
+enum v4l2_bitrate_mode {
+ V4L2_BITRATE_NONE = 0, /* not specified */
+ V4L2_BITRATE_CBR, /* constant bitrate */
+ V4L2_BITRATE_VBR, /* variable bitrate */
+};
+struct v4l2_bitrate {
+ /* rates are specified in kbit/sec */
+ enum v4l2_bitrate_mode mode;
+ __u32 min;
+ __u32 target; /* use this one for CBR */
+ __u32 max;
+};

-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
+enum v4l2_mpeg_streamtype {
+ V4L2_MPEG_SS_1, /* MPEG-1 system stream */
+ V4L2_MPEG_PS_2, /* MPEG-2 program stream */
+ V4L2_MPEG_TS_2, /* MPEG-2 transport stream */
+ V4L2_MPEG_PS_DVD, /* MPEG-2 program stream with DVD header fixups */
+};
+enum v4l2_mpeg_audiotype {
+ V4L2_MPEG_AU_2_I, /* MPEG-2 layer 1 */
+ V4L2_MPEG_AU_2_II, /* MPEG-2 layer 2 */
+ V4L2_MPEG_AU_2_III, /* MPEG-2 layer 3 */
+ V4L2_MPEG_AC3, /* AC3 */
+ V4L2_MPEG_LPCM, /* LPCM */
+};
+enum v4l2_mpeg_videotype {
+ V4L2_MPEG_VI_1, /* MPEG-1 */
+ V4L2_MPEG_VI_2, /* MPEG-2 */
+};
+enum v4l2_mpeg_aspectratio {
+ V4L2_MPEG_ASPECT_SQUARE = 1, /* square pixel */
+ V4L2_MPEG_ASPECT_4_3 = 2, /* 4 : 3 */
+ V4L2_MPEG_ASPECT_16_9 = 3, /* 16 : 9 */
+ V4L2_MPEG_ASPECT_1_221 = 4, /* 1 : 2,21 */
+};

-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
+struct v4l2_mpeg_compression {
+ /* general */
+ enum v4l2_mpeg_streamtype st_type;
+ struct v4l2_bitrate st_bitrate;

-*/
+ /* transport streams */
+ __u16 ts_pid_pmt;
+ __u16 ts_pid_audio;
+ __u16 ts_pid_video;
+ __u16 ts_pid_pcr;
+
+ /* program stream */
+ __u16 ps_size;
+ __u16 reserved_1; /* align */
+
+ /* audio */
+ enum v4l2_mpeg_audiotype au_type;
+ struct v4l2_bitrate au_bitrate;
+ __u32 au_sample_rate;
+ __u8 au_pesid;
+ __u8 reserved_2[3]; /* align */
+
+ /* video */
+ enum v4l2_mpeg_videotype vi_type;
+ enum v4l2_mpeg_aspectratio vi_aspect_ratio;
+ struct v4l2_bitrate vi_bitrate;
+ __u32 vi_frame_rate;
+ __u16 vi_frames_per_gop;
+ __u16 vi_bframes_count;
+ __u8 vi_pesid;
+ __u8 reserved_3[3]; /* align */
+
+ /* misc flags */
+ __u32 closed_gops:1;
+ __u32 pulldown:1;
+ __u32 reserved_4:30; /* align */
+
+ /* I don't expect the above being perfect yet ;) */
+ __u32 reserved_5[8];
};
#endif

@@ -841,9 +869,9 @@ struct v4l2_streamparm
#define VIDIOC_ENUM_FMT _IOWR ('V', 2, struct v4l2_fmtdesc)
#define VIDIOC_G_FMT _IOWR ('V', 4, struct v4l2_format)
#define VIDIOC_S_FMT _IOWR ('V', 5, struct v4l2_format)
-#if 0
-#define VIDIOC_G_COMP _IOR ('V', 6, struct v4l2_compression)
-#define VIDIOC_S_COMP _IOW ('V', 7, struct v4l2_compression)
+#if 1 /* experimental */
+#define VIDIOC_G_MPEGCOMP _IOR ('V', 6, struct v4l2_mpeg_compression)
+#define VIDIOC_S_MPEGCOMP _IOW ('V', 7, struct v4l2_mpeg_compression)
#endif
#define VIDIOC_REQBUFS _IOWR ('V', 8, struct v4l2_requestbuffers)
#define VIDIOC_QUERYBUF _IOWR ('V', 9, struct v4l2_buffer)

--
#define printk(args...) fprintf(stderr, ## args)
-
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