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Video information
#include <mm/types.h> typedef struct mm_video_info { struct { uint16_t w; uint16_t h; } aspect_ratio; uint32_t width; uint32_t height; uint32_t capture_format; uint32_t frame_width; uint32_t frame_height; uint32_t max_bufferable_frames; uint32_t display_mode; uint32_t flags; char codec[32]; } mm_video_info_t;
The structure mm_video_info_t provides information about a video. It includes at least the members described in the table below.
Member | Type | Description |
---|---|---|
aspect_ratio | struct | The width to height aspect ratio of the video. See aspect_ratio below. |
width | uint32_t | The width of the video source, in pixels. |
height | uint32_t | Height of the video source, in pixels. |
capture_format | uint32_t | Flags for capturing additional information useful for presenting the video. See video_flags below. |
frame_width | uint32_t | The width, in pixels, of the rendered video in video memory; may be smaller than the frame width. A value different from width does not imply scaling; see “flags” below. |
frame_height | uint32_t | The height, in pixels, of the rendered video in video memory; may be smaller than the frame height. A value different from width does not imply scaling; see “flags” below. |
max_bufferable_frames | uint32_t | The maximum number of frames that can be requested for buffering by a call to the function mme_video_set_properties(). A -1 indicates that the video player does not support bufferable frames. |
display_mode | uint32_t | The video display mode. See mm_display_mode |
flags | uint32_t | Flags indicating how to handle the video display frame croppiing and scaling. |
codec | char | A character string with name of the video codec. See “Video codec” below. |
The aspect_ratio member uses whole numbers to express the video aspect ratio. These numbers only describe the height to width ratio of the image, and have no bearing on the actual width and height in pixels of the source.
Common aspect ratio values are:
Usual representations are in parentheses: “(x,y)”.
The w and h members of the structure aspect_ratio are the whole numbers used to express the aspect ratio of the image.
Width w and height h values of 0 (0,0) mean that no aspect ratio information is available.
The width and height are the actual width and height of the source image, in pixels.
The flags member of the structure mm_video_info_t uses the following values:
The function video_get_status() uses the data structure mm_video_info_t. The function mme_audio_get_status() uses the data structure mm_audio_format_t. Both these structures include a member codec.
The codec members of the structures mm_video_info_t and mm_audio_format_t hold character strings identifying the codec format for the video or audio. These strings can have a length of up to the number of bytes defined by MM_CODEC_NAME_MAX_LEN, which is currently 32 bytes.
Client applications can pass these character strings up to the end users to inform them of the codec format used by a video or audio track.
The enumerated type mm_display_mode describes a video's display mode. Its values include:
The enumerated type capture_format describes a video's capture format. Its values include:
QNX Multimedia
mm_audio_format_t, mm_bitrate_t, mm_video_audio_info_t, mme_video_properties_t, mme_audio_get_status, mme_video_get_status()
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