capabilities 字段字段：V4L2设备具备的能力

最新推荐文章于 2025-10-17 10:56:19 发布

原创最新推荐文章于 2025-10-17 10:56:19 发布 · 423 阅读

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该文定义了V4L2设备的一系列能力标志，包括视频捕获、输出、叠加、VBI处理、RDS功能以及多平面格式支持，同时还涵盖了音频、无线电和流式传输I/O等方面。

/* Values for ‘capabilities’ field /
#define V4L2_CAP_VIDEO_CAPTURE 0x00000001 / Is a video capture device /
#define V4L2_CAP_VIDEO_OUTPUT 0x00000002 / Is a video output device /
#define V4L2_CAP_VIDEO_OVERLAY 0x00000004 / Can do video overlay /
#define V4L2_CAP_VBI_CAPTURE 0x00000010 / Is a raw VBI capture device /
#define V4L2_CAP_VBI_OUTPUT 0x00000020 / Is a raw VBI output device /
#define V4L2_CAP_SLICED_VBI_CAPTURE 0x00000040 / Is a sliced VBI capture device /
#define V4L2_CAP_SLICED_VBI_OUTPUT 0x00000080 / Is a sliced VBI output device /
#define V4L2_CAP_RDS_CAPTURE 0x00000100 / RDS data capture /
#define V4L2_CAP_VIDEO_OUTPUT_OVERLAY 0x00000200 / Can do video output overlay /
#define V4L2_CAP_HW_FREQ_SEEK 0x00000400 / Can do hardware frequency seek /
#define V4L2_CAP_RDS_OUTPUT 0x00000800 / Is an RDS encoder */

/* Is a video capture device that supports multiplanar formats /
#define V4L2_CAP_VIDEO_CAPTURE_MPLANE 0x00001000
/ Is a video output device that supports multiplanar formats /
#define V4L2_CAP_VIDEO_OUTPUT_MPLANE 0x00002000
/ Is a video mem-to-mem device that supports multiplanar formats /
#define V4L2_CAP_VIDEO_M2M_MPLANE 0x00004000
/ Is a video mem-to-mem device */
#define V4L2_CAP_VIDEO_M2M 0x00008000

#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_MODULATOR 0x00080000 / has a modulator */

#define V4L2_CAP_SDR_CAPTURE 0x00100000 /* Is a SDR capture device /
#define V4L2_CAP_EXT_PIX_FORMAT 0x00200000 / Supports the extended pixel format */

#define V4L2_CAP_READWRITE 0x01000000 /* read/write systemcalls /
#define V4L2_CAP_ASYNCIO 0x02000000 / async I/O /
#define V4L2_CAP_STREAMING 0x04000000 / streaming I/O ioctls */

#define V4L2_CAP_DEVICE_CAPS 0x80000000 /* sets device capabilities field */