1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 2 3.. _video_types: 4 5**************** 6Video Data Types 7**************** 8 9 10.. _video-format-t: 11 12video_format_t 13============== 14 15The ``video_format_t`` data type defined by 16 17 18.. code-block:: c 19 20 typedef enum { 21 VIDEO_FORMAT_4_3, /* Select 4:3 format */ 22 VIDEO_FORMAT_16_9, /* Select 16:9 format. */ 23 VIDEO_FORMAT_221_1 /* 2.21:1 */ 24 } video_format_t; 25 26is used in the VIDEO_SET_FORMAT function (??) to tell the driver which 27aspect ratio the output hardware (e.g. TV) has. It is also used in the 28data structures video_status (??) returned by VIDEO_GET_STATUS (??) 29and video_event (??) returned by VIDEO_GET_EVENT (??) which report 30about the display format of the current video stream. 31 32 33.. _video-displayformat-t: 34 35video_displayformat_t 36===================== 37 38In case the display format of the video stream and of the display 39hardware differ the application has to specify how to handle the 40cropping of the picture. This can be done using the 41VIDEO_SET_DISPLAY_FORMAT call (??) which accepts 42 43 44.. code-block:: c 45 46 typedef enum { 47 VIDEO_PAN_SCAN, /* use pan and scan format */ 48 VIDEO_LETTER_BOX, /* use letterbox format */ 49 VIDEO_CENTER_CUT_OUT /* use center cut out format */ 50 } video_displayformat_t; 51 52as argument. 53 54 55.. _video-stream-source-t: 56 57video_stream_source_t 58===================== 59 60The video stream source is set through the VIDEO_SELECT_SOURCE call 61and can take the following values, depending on whether we are replaying 62from an internal (demuxer) or external (user write) source. 63 64 65.. code-block:: c 66 67 typedef enum { 68 VIDEO_SOURCE_DEMUX, /* Select the demux as the main source */ 69 VIDEO_SOURCE_MEMORY /* If this source is selected, the stream 70 comes from the user through the write 71 system call */ 72 } video_stream_source_t; 73 74VIDEO_SOURCE_DEMUX selects the demultiplexer (fed either by the 75frontend or the DVR device) as the source of the video stream. If 76VIDEO_SOURCE_MEMORY is selected the stream comes from the application 77through the **write()** system call. 78 79 80.. _video-play-state-t: 81 82video_play_state_t 83================== 84 85The following values can be returned by the VIDEO_GET_STATUS call 86representing the state of video playback. 87 88 89.. code-block:: c 90 91 typedef enum { 92 VIDEO_STOPPED, /* Video is stopped */ 93 VIDEO_PLAYING, /* Video is currently playing */ 94 VIDEO_FREEZED /* Video is freezed */ 95 } video_play_state_t; 96 97 98.. c:type:: video_command 99 100struct video_command 101==================== 102 103The structure must be zeroed before use by the application This ensures 104it can be extended safely in the future. 105 106 107.. code-block:: c 108 109 struct video_command { 110 __u32 cmd; 111 __u32 flags; 112 union { 113 struct { 114 __u64 pts; 115 } stop; 116 117 struct { 118 /* 0 or 1000 specifies normal speed, 119 1 specifies forward single stepping, 120 -1 specifies backward single stepping, 121 >>1: playback at speed/1000 of the normal speed, 122 <-1: reverse playback at (-speed/1000) of the normal speed. */ 123 __s32 speed; 124 __u32 format; 125 } play; 126 127 struct { 128 __u32 data[16]; 129 } raw; 130 }; 131 }; 132 133 134.. _video-size-t: 135 136video_size_t 137============ 138 139 140.. code-block:: c 141 142 typedef struct { 143 int w; 144 int h; 145 video_format_t aspect_ratio; 146 } video_size_t; 147 148 149.. c:type:: video_event 150 151struct video_event 152================== 153 154The following is the structure of a video event as it is returned by the 155VIDEO_GET_EVENT call. 156 157 158.. code-block:: c 159 160 struct video_event { 161 __s32 type; 162 #define VIDEO_EVENT_SIZE_CHANGED 1 163 #define VIDEO_EVENT_FRAME_RATE_CHANGED 2 164 #define VIDEO_EVENT_DECODER_STOPPED 3 165 #define VIDEO_EVENT_VSYNC 4 166 long timestamp; 167 union { 168 video_size_t size; 169 unsigned int frame_rate; /* in frames per 1000sec */ 170 unsigned char vsync_field; /* unknown/odd/even/progressive */ 171 } u; 172 }; 173 174 175.. c:type:: video_status 176 177struct video_status 178=================== 179 180The VIDEO_GET_STATUS call returns the following structure informing 181about various states of the playback operation. 182 183 184.. code-block:: c 185 186 struct video_status { 187 int video_blank; /* blank video on freeze? */ 188 video_play_state_t play_state; /* current state of playback */ 189 video_stream_source_t stream_source; /* current source (demux/memory) */ 190 video_format_t video_format; /* current aspect ratio of stream */ 191 video_displayformat_t display_format;/* selected cropping mode */ 192 }; 193 194If video_blank is set video will be blanked out if the channel is 195changed or if playback is stopped. Otherwise, the last picture will be 196displayed. play_state indicates if the video is currently frozen, 197stopped, or being played back. The stream_source corresponds to the 198selected source for the video stream. It can come either from the 199demultiplexer or from memory. The video_format indicates the aspect 200ratio (one of 4:3 or 16:9) of the currently played video stream. 201Finally, display_format corresponds to the selected cropping mode in 202case the source video format is not the same as the format of the output 203device. 204 205 206.. c:type:: video_still_picture 207 208struct video_still_picture 209========================== 210 211An I-frame displayed via the VIDEO_STILLPICTURE call is passed on 212within the following structure. 213 214 215.. code-block:: c 216 217 /* pointer to and size of a single iframe in memory */ 218 struct video_still_picture { 219 char *iFrame; /* pointer to a single iframe in memory */ 220 int32_t size; 221 }; 222 223 224.. _video_caps: 225 226video capabilities 227================== 228 229A call to VIDEO_GET_CAPABILITIES returns an unsigned integer with the 230following bits set according to the hardwares capabilities. 231 232 233.. code-block:: c 234 235 /* bit definitions for capabilities: */ 236 /* can the hardware decode MPEG1 and/or MPEG2? */ 237 #define VIDEO_CAP_MPEG1 1 238 #define VIDEO_CAP_MPEG2 2 239 /* can you send a system and/or program stream to video device? 240 (you still have to open the video and the audio device but only 241 send the stream to the video device) */ 242 #define VIDEO_CAP_SYS 4 243 #define VIDEO_CAP_PROG 8 244 /* can the driver also handle SPU, NAVI and CSS encoded data? 245 (CSS API is not present yet) */ 246 #define VIDEO_CAP_SPU 16 247 #define VIDEO_CAP_NAVI 32 248 #define VIDEO_CAP_CSS 64 249