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-rw-r--r--dvb-spec/dvbapi/video.tex101
1 files changed, 56 insertions, 45 deletions
diff --git a/dvb-spec/dvbapi/video.tex b/dvb-spec/dvbapi/video.tex
index 7300c95c0..3fa066b87 100644
--- a/dvb-spec/dvbapi/video.tex
+++ b/dvb-spec/dvbapi/video.tex
@@ -1,11 +1,22 @@
\devsec{DVB Video Device}
The DVB video device controls the MPEG2 video decoder of the DVB hardware.
-It can be accessed through \texttt{/dev/ost/video}.
-The include file \texttt{ost/video.h} defines the data types and lists
-all I/O calls. Please note that some DVB cards don't have their own
-MPEG decoder, which results in the omission of the audio and video
-device as well as the video4linux device.
+It can be accessed through \texttt{/dev/dvb/adapter0/video0}.
+Data types and and ioctl definitions can be accessed by including
+\texttt{linux/dvb/video.h} in your application.
+
+
+Note that the DVB video device only controls decoding of the MPEG
+video stream, not its presentation on the TV or computer screen.
+On PCs this is typically handled by an associated video4linux device, e.g.
+\texttt{/dev/video}, which allows scaling and defining output windows.
+
+Some DVB cards don't have their own MPEG decoder, which results in the omission
+of the audio and video device as well as the video4linux device.
+
+The ioctls that deal with SPUs (sub picture units) and navigation
+packets are only supported on some MPEG decoders made for DVD playback.
+
\devsubsec{Video Data Types}
@@ -17,7 +28,7 @@ The \texttt{video\_format\_t} data type defined by
typedef enum {
VIDEO_FORMAT_4_3,
VIDEO_FORMAT_16_9
-} video\_format_t;
+} video_format_t;
\end{verbatim}
is used in the VIDEO\_SET\_FORMAT function (\ref{videosetformat}) to
tell the driver which aspect ratio the output hardware (e.g. TV) has.
@@ -26,7 +37,7 @@ returned by VIDEO\_GET\_STATUS (\ref{videogetstatus}) and
video\_event (\ref{videoevent}) returned by VIDEO\_GET\_EVENT (\ref{videogetevent})
which report about the display format of the current video stream.
-\devsubsubsec{videoDisplayFormat\_t}
+\devsubsubsec{video\_display\_format\_t}
\label{videodispformat}
In case the display format of the video stream and of the
@@ -39,7 +50,7 @@ typedef enum {
VIDEO_PAN_SCAN,
VIDEO_LETTER_BOX,
VIDEO_CENTER_CUT_OUT
-} video\_displayformat_t;
+} video_display_format_t;
\end{verbatim}
as argument.
@@ -53,7 +64,7 @@ replaying from an internal (demuxer) or external (user write) source.
typedef enum {
VIDEO_SOURCE_DEMUX,
VIDEO_SOURCE_MEMORY
-} video\_stream\_source_t;
+} video_stream_source_t;
\end{verbatim}
VIDEO\_SOURCE\_DEMUX selects the demultiplexer (fed
either by the frontend or the DVR device) as the source of
@@ -71,35 +82,35 @@ typedef enum {
VIDEO_STOPPED,
VIDEO_PLAYING,
VIDEO_FREEZED
-} video\_play\_state_t;
+} video_play_state_t;
\end{verbatim}
-\devsubsubsec{video event}
+\devsubsubsec{struct video\_event}
\label{videoevent}
The following is the structure of a video event as it is returned by
the VIDEO\_GET\_EVENT call.
\begin{verbatim}
-struct video\_event {
+struct video_event {
int32_t type;
time_t timestamp;
union {
- video\_format_t video\_format;
+ video_format_t video_format;
} u;
};
\end{verbatim}
-\devsubsubsec{video status}
+\devsubsubsec{struct video\_status}
\label{videostatus}
The VIDEO\_GET\_STATUS call returns the following structure informing
about various states of the playback operation.
\begin{verbatim}
-struct video\_status {
- boolean video\_blank;
- video\_play\_state_t play\_state;
- video\_stream\_source_t stream\_source;
- video\_format_t video\_format;
- video\_displayformat_t display\_format;
+struct video_status {
+ boolean video_blank;
+ video_play_state_t play_state;
+ video_stream_source_t stream_source;
+ video_format_t video_format;
+ video_displayformat_t display_format;
};
\end{verbatim}
If video\_blank is set video will be blanked out if the channel is changed or
@@ -113,13 +124,13 @@ Finally, display\_format corresponds to the selected cropping mode in case the
source video format is not the same as the format of the output device.
-\devsubsubsec{video display still picture}
+\devsubsubsec{struct video\_still\_picture}
\label{videostill}
An I-frame displayed via the VIDEO\_STILLPICTURE call is passed on
within the following structure.
\begin{verbatim}
/* pointer to and size of a single iframe in memory */
-struct video\_still\_picture {
+struct video_still_picture {
char *iFrame;
int32_t size;
};
@@ -162,19 +173,19 @@ typedef enum {
VIDEO_SYSTEM_NTSC60,
VIDEO_SYSTEM_PAL60,
VIDEO_SYSTEM_PALM60
-} video\_system_t;
+} video_system_t;
\end{verbatim}
-\devsubsubsec{video highlights}
+\devsubsubsec{struct video\_highlight}
\label{vhilite}
Calling the ioctl VIDEO\_SET\_HIGHLIGHTS posts the SPU highlight
information. The call expects the following format for that information:
-
+
\begin{verbatim}
typedef
-struct video\_highlight {
+struct video_highlight {
boolean active; /* 1=show highlight, 0=hide highlight */
uint8_t contrast1; /* 7- 4 Pattern pixel contrast */
/* 3- 0 Background pixel contrast */
@@ -190,7 +201,7 @@ struct video\_highlight {
uint32_t xpos; /* 23-22 button color number */
/* 21-12 start x */
/* 9- 0 end x */
-} video\_highlight_t;
+} video_highlight_t;
\end{verbatim}
@@ -200,10 +211,10 @@ Calling VIDEO\_SET\_SPU deactivates or activates SPU decoding,
according to the following format:
\begin{verbatim}
typedef
-struct video\_spu {
+struct video_spu {
boolean active;
- int stream\_id;
-} video\_spu\_t;
+ int stream_id;
+} video_spu_t;
\end{verbatim}
@@ -212,10 +223,10 @@ struct video\_spu {
The following structure is used to set the SPU palette by calling VIDEO\_SPU\_PALETTE:
\begin{verbatim}
typedef
-struct video\_spu\_palette{ /* SPU Palette information */
+struct video_spu_palette{
int length;
uint8_t *palette;
-} video\_spu\_palette_t;
+} video_spu_palette_t;
\end{verbatim}
\devsubsubsec{video NAVI pack}
@@ -224,10 +235,10 @@ In order to get the navigational data the following structure has to
be passed to the ioctl VIDEO\_GET\_NAVI:
\begin{verbatim}
typedef
-struct video\_navi\_pack{
- int length; /* 0 ... 1024 */
+struct video_navi_pack{
+ int length; /* 0 ... 1024 */
uint8_t data[1024];
-} video\_navi\_pack_t;
+} video_navi_pack_t;
\end{verbatim}
@@ -235,7 +246,7 @@ struct video\_navi\_pack{
\label{vattrib}
The following attributes can be set by a call to VIDEO\_SET\_ATTRIBUTES:
\begin{verbatim}
-typedef uint16_t video\_attributes_t;
+typedef uint16_t video_attributes_t;
/* bits: descr. */
/* 15-14 Video compression mode (0=MPEG-1, 1=MPEG-2) */
/* 13-12 TV system (0=525/60, 1=625/50) */
@@ -255,7 +266,7 @@ typedef uint16_t video\_attributes_t;
\function{open()}{
int open(const char *deviceName, int flags);}{
- This system call opens a named video device (e.g. /dev/ost/video)
+ This system call opens a named video device (e.g. /dev/dvb/adapter0/video0)
for subsequent use.
When an open() call has succeeded, the device will be ready for use.
@@ -376,7 +387,7 @@ EINTERNAL & Internal error, possibly in the communication with
\ifunction{VIDEO\_SELECT\_SOURCE}{
- int ioctl(fd, int request = VIDEO\_SELECT\_SOURCE, videoStreamSource\_t source);}{
+ int ioctl(fd, int request = VIDEO\_SELECT\_SOURCE, video\_stream\_source\_t source);}{
This ioctl call informs the video device which source shall be used
for the input data. The possible sources are demux or memory. If
memory is selected, the data is fed to the video device through
@@ -384,7 +395,7 @@ EINTERNAL & Internal error, possibly in the communication with
}{
int fd & File descriptor returned by a previous call to open().\\
int request& Equals VIDEO\_SELECT\_SOURCE for this command. \\
- videoStreamSource\_t source&Indicates which source shall be used for the Video stream.\\
+ video\_stream\_source\_t source&Indicates which source shall be used for the Video stream.\\
}{
EBADF& fd is not a valid open file descriptor \\
EINTERNAL & Internal error, possibly in the communication with the DVB subsystem.\\
@@ -446,13 +457,13 @@ EOVERFLOW & \\
\ifunction{VIDEO\_SET\_DISPLAY\_FORMAT}{
\label{videosetdisplayformat}
- int ioctl(fd, int request = VIDEO\_SET\_DISPLAY\_FORMAT, videoDisplayFormat\_t format);}{
+ int ioctl(fd, int request = VIDEO\_SET\_DISPLAY\_FORMAT, video\_display\_format\_t format);}{
This ioctl call asks the Video Device to select the video format to be applied
by the MPEG chip on the video.
}{
int fd & File descriptor returned by a previous call to open().\\
int request & Equals VIDEO\_SET\_DISPLAY\_FORMAT for this command.\\
- videoDisplayFormat\_t format & Selects the video format to be used.\\
+ video\_display\_format\_t format & Selects the video format to be used.\\
}{
EBADF& fd is not a valid open file descriptor \\
EINTERNAL & Internal error.\\
@@ -578,7 +589,7 @@ EOVERFLOW & \\
\ifunction{VIDEO\_SET\_SYSTEM}{
\label{videosetsystem}
- int ioctl(fd, int request = VIDEO\_SET\_SYSTEM , videoSystem\_t system);
+ int ioctl(fd, int request = VIDEO\_SET\_SYSTEM , video\_system\_t system);
}{
This ioctl sets the television output format. The format (see section
\ref{videosys}) may vary from the color format of the displayed MPEG
@@ -587,7 +598,7 @@ EOVERFLOW & \\
}{
int fd & File descriptor returned by a previous call to open().\\
int request & Equals VIDEO\_SET\_FORMAT for this command.\\
- videoSystem\_t system& video system of TV output.\\
+ video\_system\_t system& video system of TV output.\\
}{
EBADF& fd is not a valid open file descriptor \\
EINVAL& system is not a valid or supported video system.\\
@@ -663,7 +674,7 @@ EOVERFLOW & \\
\ifunction{VIDEO\_SET\_ATTRIBUTES}{
\label{videosetattributes}
- int ioctl(fd, int request = VIDEO\_SET\_ATTRIBUTE ,videoAttributes\_t
+ int ioctl(fd, int request = VIDEO\_SET\_ATTRIBUTE ,video\_attributes\_t
vattr)
}{
This ioctl is intended for DVD playback and allows you to set
@@ -673,7 +684,7 @@ EOVERFLOW & \\
}{
int fd & File descriptor returned by a previous call to open().\\
int request & Equals VIDEO\_SET\_ATTRIBUTE for this command.\\
- videoAttributes\_t vattr& video attributes according to section \ref{vattrib}.\\
+ video\_attributes\_t vattr& video attributes according to section \ref{vattrib}.\\
}{
EBADF& fd is not a valid open file descriptor \\
EINVAL& input is not a valid attribute setting.\\
generated by cgit v1.2.3 (git 2.25.1) at 2025-02-03 17:26:47 +0000