Explore video sample applications - Qualcomm Dragonwing Documentation

You can use the video functionality at the native layer by using the Qualcomm IM SDK framework or by using the V4L2 interfaces. Qualcomm provides GStreamer and V4L2-based sample applications to run the video sample use cases.

GStreamer samples

The Qualcomm IM SDK includes sample GStreamer applications for video playback. Note For information on sample GStreamer applications supported on different SoCs, see Multimedia sample applications. For information about the prerequisites for the GStreamer applications, see Run sample applications for video and audio. The following table lists the methods and the corresponding sample video test cases:

Table: Methods to test video use cases

Method	Use case
Using `gst-launch-1.0`	Video playback
	Audio-video playback
	Video recording
Using the GStreamer application	Video playback

V4L2 samples

The iris_v4l2_test sample video test application uses Linux V4L2 interfaces to simulate several basic encoder and decoder behaviors. For more information, see sample V4L2 application. Qualcomm Linux supports the following video APIs:

GStreamer APIs: The Qualcomm GStreamer plugins are open-source GStreamer framework compliant. For more information about the GStreamer based plugins, see Qualcomm IM SDK.
V4L2 APIs: The Adreno VPU driver follows a standard V4L2-compliant call flow. The V4L2 APIs section provides information related to V4L2 APIs, commands, controls, and events.

Configure GStreamer and V4L2 APIs

Qualcomm offers GStreamer-based plugins that you can integrate into your media pipeline. For information on the GStreamer-based plugins, see Configure Qualcomm GStreamer plugins.
The Adreno VPU driver uses the V4L2 interface to support video encoding and decoding for all clients that follow the V4L2 guidance.

GStreamer APIs

For information on the GStreamer application development and pipeline creation, see Building an Application.

Configure GStreamer APIs

For information on configuring the GStreamer element property for different features and respective plugins, see Configure Qualcomm GStreamer plugins.

V4L2 APIs

This section describes V4L2 device nodes, file operations, commands, controls, and events for the decoder and encoder.

VPU driver nodes

The device registers the VPU driver during the boot-up process and assigns the device node number to the qcom-multimedia-proprietary-image.

VPU driver node for decoder: /dev/video32
VPU driver node for encoder: /dev/video33

Note:

For qcom-multimedia-image, the VPU driver assigns the device node to any of the two device nodes starting from video0 to video27.

V4L2 file operations

The Adreno VPU driver supports the following V4L2 file operations:

Table: V4L2 file operations

Operation	Description
`open`	Opens the video device file descriptor (FD) that’s used to communicate with the VPU driver using the input/output control `ioctl` commands
`close`	Closes the video device upon the completion of a video use case, and releases all the VPU driver resources related to the video device
`poll`	Waits for the events from the VPU driver
`ioctl`	Sends commands or controls to the VPU device

V4L2 common commands for decoder and encoder

The VPU driver supports the following ioctl commands for the video decoder and encoder use cases:

VIDIOC_ENUM_FMT
VIDIOC_TRY_FMT
VIDIOC_G_FMT
VIDIOC_S_FMT
VIDIOC_ENUM_FRAMESIZES
VIDIOC_REQBUFS
VIDIOC_QUERY_BUF
VIDIOC_CREATE_BUF
VIDIOC_PREPARE_BUF
VIDIOC_QBUF
VIDIOC_DQBUF
VIDIOC_STREAMON
VIDIOC_STREAMOFF
VIDIOC_QUERYCAP
VIDIOC_QUERYCTRL
VIDIOC_QUERYMENU
VIDIOC_SUBSCRIBE_EVENT
VIDIOC_UNSUBSCRIBE_EVENT
VIDIOC_G_SELECTION
VIDIOC_G_CTRL
VIDIOC_S_CTRL

V4L2 video decoder

This section provides information on the Adreno VPU decoder device nodes, supported controls, commands, and events. For the procedure to open a VPU decoder node, see VPU driver nodes. V4L2 ioctl commands for decoder For descriptions of the standard ioctl commands, see Video for Linux API Function Reference. Apart from the common commands, the VPU driver also supports the following ioctl commands for the video decoder use cases:

VIDIOC_TRY_DECODER_CMD
VIDIOC_DECODER_CMD

As specified in the Memory-to-Memory Stateful Video Decoder Interface, the decoder supports all the mandatory commands required for the video decoder use cases. V4L2 open-source controls for decoder For descriptions of the standard open-source controls, see Codec Control Reference. The VPU driver supports the following open-source controls for the video decoder use cases:

Table: V4L2 open-source controls for decoder

Control ID	Purpose	Dynamic/Static
`V4L2_CID_MPEG_VIDEO_H264_PROFILE`	H.264 decoder profile	Static
`V4L2_CID_MPEG_VIDEO_HEVC_PROFILE`	HEVC decoder profile	Static
`V4L2_CID_MPEG_VIDEO_VP9_PROFILE`	VP9 decoder profile	Static
`V4L2_CID_MPEG_VIDEO_H264_LEVEL`	H.264 decoder level	Static
`V4L2_CID_MPEG_VIDEO_HEVC_LEVEL`	HEVC decoder level	Static
`V4L2_CID_MPEG_VIDEO_VP9_LEVEL`	VP9 decoder level	Static
`V4L2_CID_MPEG_VIDEO_HEVC_TIER`	HEVC decoder tier	Static

The decoder supports the following V4L2 open-source events:

V4L2_EVENT_EOS
V4L2_EVENT_SOURCE_CHANGE
V4L2_EVENT_CTRL

The decoder supports the following V4L2 commands:

V4L2_DEC_CMD_START
V4L2_DEC_CMD_STOP

V4L2 video encoder

This section provides the information on the Adreno VPU encoder device nodes, supported controls, commands, and events. For the procedure to open a VPU encoder node, see VPU driver nodes. V4L2 ioctl commands for encoder For descriptions of the standard ioctl commands, see Function Reference. Apart from the common commands, the VPU driver also supports the following ioctl commands for the encode use cases:

VIDIOC_ENUM_FRAMEINTERVALS
VIDIOC_S_SELECTION
VIDIOC_S_PARM
VIDIOC_G_PARM
VIDIOC_TRY_ENCODER_CMD
VIDIOC_ENCODER_CMD

As specified in the Memory-to-Memory Stateful Video Encoder Interface, the encoder supports all the mandatory commands required for the video encoder use cases. V4L2 open-source controls for encoder For descriptions of the standard open-source controls, see Codec Control Reference. The VPU driver supports the following open-source controls for the video encoder use cases:

Table: V4L2 open-source controls for encoder

Control ID	Purpose	Dynamic/Static
`V4L2_CID_MPEG_VIDEO_H264_PROFILE`	H.264 encoder profile	Static
`V4L2_CID_MPEG_VIDEO_HEVC_PROFILE`	HEVC encoder profile	Static
`V4L2_CID_MPEG_VIDEO_H264_LEVEL`	H.264 encoder level	Static
`V4L2_CID_MPEG_VIDEO_HEVC_LEVEL`	HEVC encoder level	Static
`V4L2_CID_MPEG_VIDEO_HEVC_TIER`	H.264 encoder tier	Static
`V4L2_CID_HFLIP`	Horizontal flip	Both
`V4L2_CID_VFLIP`	Vertical flip	Both
`V4L2_CID_ROTATE`	Rotation	Static
`V4L2_CID_MPEG_VIDEO_HEADER_MODE`	Header mode	Static
`V4L2_CID_MPEG_VIDEO_PREPEND_SPSPPS_TO_IDR`	SPS/PPS with Instantaneous Decoder Refresh (IDR) frame	Static
`V4L2_CID_MPEG_VIDEO_FORCE_KEY_FRAME`	Request force sync frame	Both
`V4L2_CID_MPEG_VIDEO_BITRATE`	Average bit rate	Both
`V4L2_CID_MPEG_VIDEO_BITRATE_PEAK`	Peak bit rate	Both
`V4L2_CID_MPEG_VIDEO_BITRATE_MODE`	Rate control	Static
`V4L2_CID_MPEG_VIDEO_FRAME_SKIP_MODE`	Frame skip mode	Static
`V4L2_CID_MPEG_VIDEO_FRAME_RC_ENABLE`	RC enable/disable	Static
`V4L2_CID_MPEG_VIDEO_GOP_SIZE`	Group-of-pictures size	Both
`V4L2_CID_MPEG_VIDEO_B_FRAMES`	B-Frames	Static
`V4L2_CID_MPEG_VIDEO_LTR_COUNT`	LTR frame count	Static
`V4L2_CID_MPEG_VIDEO_USE_LTR_FRAMES`	Use LTR	Both
`V4L2_CID_MPEG_VIDEO_FRAME_LTR_INDEX`	Mark LTR	Both
`V4L2_CID_MPEG_VIDEO_BASELAYER_PRIORITY_ID`	Set base layer ID for layer encode	Static
`V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD_TYPE`	Intra-refresh	Static
`V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD`	Intra-refresh period	Both
`V4L2_CID_MPEG_VIDEO_H264_MIN_QP`	H.264 minimum Quantization Parameter (QP)	Static
`V4L2_CID_MPEG_VIDEO_HEVC_MIN_QP`	HEVC minimum QP	Static
`V4L2_CID_MPEG_VIDEO_H264_MAX_QP`	H.264 maximum QP	Static
`V4L2_CID_MPEG_VIDEO_HEVC_MAX_QP`	HEVC maximum QP	Static
`V4L2_CID_MPEG_VIDEO_H264_I_FRAME_MIN_QP`	H.264 I-frame minimum QP	Static
`V4L2_CID_MPEG_VIDEO_HEVC_I_FRAME_MIN_QP`	HEVC I-frame minimum QP	Static
`V4L2_CID_MPEG_VIDEO_H264_P_FRAME_MIN_QP`	H.264 P-Frame minimum QP	Static
`V4L2_CID_MPEG_VIDEO_HEVC_P_FRAME_MIN_QP`	HEVC P-Frame minimum QP	Static
`V4L2_CID_MPEG_VIDEO_H264_B_FRAME_MIN_QP`	H.264 B-Frame minimum QP	Static
`V4L2_CID_MPEG_VIDEO_HEVC_B_FRAME_MIN_QP`	HEVC B-Frame minimum QP	Static
`V4L2_CID_MPEG_VIDEO_H264_I_FRAME_MAX_QP`	H.264 I-Frame maximum QP	Static
`V4L2_CID_MPEG_VIDEO_HEVC_I_FRAME_MAX_QP`	HEVC I-Frame maximum QP	Static
`V4L2_CID_MPEG_VIDEO_H264_P_FRAME_MAX_QP`	H.264 P-Frame maximum QP	Static
`V4L2_CID_MPEG_VIDEO_HEVC_P_FRAME_MAX_QP`	HEVC P-Frame maximum QP	Static
`V4L2_CID_MPEG_VIDEO_H264_B_FRAME_MAX_QP`	H.264 B-Frame maximum QP	Static
`V4L2_CID_MPEG_VIDEO_HEVC_B_FRAME_MAX_QP`	HEVC B-Frame maximum QP	Static
`V4L2_CID_MPEG_VIDEO_HEVC_I_FRAME_QP`	HEVC I-Frame QP	Both
`V4L2_CID_MPEG_VIDEO_H264_I_FRAME_QP`	H.264 I-Frame QP	Both
`V4L2_CID_MPEG_VIDEO_HEVC_P_FRAME_QP`	HEVC P-Frame QP	Both
`V4L2_CID_MPEG_VIDEO_H264_P_FRAME_QP`	H.264 P-Frame QP	Both
`V4L2_CID_MPEG_VIDEO_HEVC_B_FRAME_QP`	HEVC B-Frame QP	Both
`V4L2_CID_MPEG_VIDEO_H264_B_FRAME_QP`	H.264 B-Frame QP	Both
`V4L2_CID_MPEG_VIDEO_HEVC_HIER_CODING_TYPE`	HEVC Hier coding type	Static
`V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_TYPE`	H.264 Hier coding type	Static
`V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING`	H.264 Hier coding	Static
`V4L2_CID_MPEG_VIDEO_HEVC_HIER_CODING_LAYER`	HEVC Hier layer count	Both
`V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER`	H.264 Hier layer count	Both
`V4L2_CID_MPEG_VIDEO_H264_HIER_CODING_L0_BR`	H.264 layer 0-bit rate	Both
`V4L2_CID_MPEG_VIDEO_HEVC_HIER_CODING_L0_BR`	HEVC layer 0-bit rate	Both
`V4L2_CID_MPEG_VIDEO_H264_HIER_CODING_L1_BR`	H.264 layer 1-bit rate	Both
`V4L2_CID_MPEG_VIDEO_HEVC_HIER_CODING_L1_BR`	HEVC layer 1-bit rate	Both
`V4L2_CID_MPEG_VIDEO_H264_HIER_CODING_L2_BR`	H.264 layer 2-bit rate	Both
`V4L2_CID_MPEG_VIDEO_HEVC_HIER_CODING_L2_BR`	HEVC layer 2-bit rate	Both
`V4L2_CID_MPEG_VIDEO_H264_HIER_CODING_L3_BR`	H.264 layer 3-bit rate	Both
`V4L2_CID_MPEG_VIDEO_HEVC_HIER_CODING_L3_BR`	HEVC layer 3-bit rate	Both
`V4L2_CID_MPEG_VIDEO_H264_HIER_CODING_L4_BR`	H.264 layer 4-bit rate	Both
`V4L2_CID_MPEG_VIDEO_HEVC_HIER_CODING_L4_BR`	HEVC layer 4-bit rate	Both
`V4L2_CID_MPEG_VIDEO_H264_HIER_CODING_L5_BR`	H.264 layer 5-bit rate	Both
`V4L2_CID_MPEG_VIDEO_HEVC_HIER_CODING_L5_BR`	HEVC layer 5-bit rate	Both
`V4L2_CID_MPEG_VIDEO_H264_ENTROPY_MODE`	H.264 entropy mode	Static
`V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE`	Encode slice mode	Static
`V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_BYTES`	Maximum bytes in slice	Static
`V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_MB`	Maximum macroblocks in slice	Static

Set all static configuration options after setting the formats on both the planes and before requesting buffers on either of the plane. Call the dynamic parameters after setting the formats on both planes. For information on the V4L2 controls for encoder, see Codec Control Reference. The supported open-source events for encoder are:

V4L2_EVENT_EOS
V4L2_EVENT_CTRL

The supported open-source commands for encoder are:

V4L2_ENC_CMD_START
V4L2_ENC_CMD_STOP

Configure V4L2 APIs

Use the V4L2 control IDs, accepted format, accepted ranges, and sample code information, provided in this section, to configure and manage different video features on your device. B-Frame encode You can configure the VPU driver to set up B-Frames in an encoder session using the VIDIOC_S_CTRL ioctl system call. Set the B-Frame encode configuration before setting the VIDIOC_STREAMON on an output plane. The VPU driver supports B-Frame encode only with Hierarchical coding. This feature doesn’t support dynamic configuration.

Table: Control IDs for B-Frame encode

Control ID for H.264 and HEVC codecs	Accepted format	Range
`V4L2_CID_MPEG_VIDEO_B_FRAMES`	Integer	0: Disable B-Frame 1: Enable single B-Frame

The following code sample shows the static configuration for a single B-Frame:

v4l2_control control;
int ret = 0;
int bframes = 1;
memset(&control, 0, sizeof(control));
control.id = V4L2_CID_MPEG_VIDEO_B_FRAMES;
control.value = bframes;
ret = ioctl(mDriverFd, VIDIOC_S_CTRL, &control);// mDriverFd returned from open() system call
if (ret) {
    return -1;
}
memset(&control, 0, sizeof(control));
control.id = V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_TYPE;
control.value = 0;// V4L2_MPEG_VIDEO_HEVC_HIERARCHICAL_CODING_B
ret = ioctl(mDriverFd, VIDIOC_S_CTRL, &control);// mDriverFd returned from open() system call
if (ret) {
    return -1;
}
memset(&control, 0, sizeof(control));
control.id = V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER;
control.value = 1;//Enable 1 layer
ret = ioctl(mDriverFd, VIDIOC_S_CTRL, &control);// mDriverFd returned from open() system call
if (ret) {
    return -1;
}

Encoder initial QP override You can configure the VPU driver to override the initial frame quantization parameter (QP) for I-Frames, P-Frames, and B-Frames to an intended value of encoded frames. You can override using the VIDIOC_S_CTRL ioctl system call. The QP override provides the flexibility to set the initial frame QP for I-Frame only, or P-Frame only, or B-Frame only, or I-frame and P-Frame only, or P-Frame and B-Frame only, or combinations of these frames. Set the encoder initial QP override configuration before the VIDIOC_STREAMON on an output plane and is only applicable to an encoder session.

Table: Control IDs for encoder initial QP override

Control ID for H.264 codec	Accepted format	QP range
`V4L2_CID_MPEG_VIDEO_H264_I_FRAME_QP`	Integer	Example according to the codec standard: 1 to 51 for 8-bit 1 to 63 (-12 to 51) for 10-bit
`V4L2_CID_MPEG_VIDEO_H264_P_FRAME_QP`	Integer
`V4L2_CID_MPEG_VIDEO_H264_B_FRAME_QP`	Integer
Control ID for HEVC codec	Accepted format	QP range
`V4L2_CID_MPEG_VIDEO_HEVC_I_FRAME_QP`	Integer	Example according to the codec standard: 1 to 51 for 8-bit 1 to 63 (-12 to 51) for 10-bit
`V4L2_CID_MPEG_VIDEO_HEVC_P_FRAME_QPI`	Integer
`V4L2_CID_MPEG_VIDEO_HEVC_B_FRAME_QP`	Integer

The following code sample shows the static configuration parameters to set:

40 as an initial QP for the I-Frame
35 as an initial QP for the P-Frame
B-Frame for the H.264 session

v4l2_control control;
int ret = 0;
memset(&control, 0, sizeof(control));
control.id = V4L2_CID_MPEG_VIDEO_H264_I_FRAME_QP;
control.value = 40;
ret = ioctl(mDriverFd, VIDIOC_S_CTRL, &control);// mDriverFd returned from open() system call
if (ret) {
    return -1;
}
memset(&control, 0, sizeof(control));
control.id = V4L2_CID_MPEG_VIDEO_H264_P_FRAME_QP;
control.value = 35;
ret = ioctl(mDriverFd, VIDIOC_S_CTRL, &control);// mDriverFd returned from open() system call
if (ret) {
    return -1;
memset(&control, 0, sizeof(control));
control.id = V4L2_CID_MPEG_VIDEO_H264_B_FRAME_QP;
control.value = 35;
ret = ioctl(mDriverFd, VIDIOC_S_CTRL, &control);// mDriverFd returned from open() system call
if (ret) {
    return -1;
}

Slice encode You can configure the VPU driver to encode a single frame into many slices using the VIDIOC_S_CTRL ioctl system call. The number of bits per slice or the number of macroblocks per slice is a slice boundary. Set the slice-encode configuration before VIDIOC_STREAMON on an output plane. The slice-encode feature doesn’t support dynamic configuration, and this configuration is applicable only to an encoder session.

Table: Control IDs for slice encode

Control ID for H.264 and HEVC codecs	Accepted format	Range
`V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE`	enum	`v4l2_mpeg_video_multi_slice_mode` Values according to the codec standard: enum `v4l2_mpeg_video_multi_slice_mode`
`V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_BYTES`	Integer	512 - MAX_BITRATE/8 Unit: bits/second
`V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_MB`	Integer	1 to 36864 Unit: Macroblocks

The following code sample shows the static configuration to encode frames with many slices and with the maximum number of macroblocks per slice set to 400:

v4l2_control control;
int ret = 0;
v4l2_mpeg_video_multi_slice_mode slicemode = V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_MB;
memset(&control, 0, sizeof(control));
control.id = V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE;
control.value = slicemode;
ret = ioctl(mDriverFd, VIDIOC_S_CTRL, &control);// mDriverFd returned from open() system call
if (ret) {
    return -1;
}
memset(&control, 0, sizeof(control));
control.id = V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_MB;
control.value = 400;
ret = ioctl(mDriverFd, VIDIOC_S_CTRL, &control);// mDriverFd returned from open() system call
if (ret) {
    return -1;
}

Intra-refresh You can configure the VPU driver to activate the intra-refresh mode and intra-refresh period using the VIDIOC_S_CTRL ioctl system call. Set the intra-refresh configuration before issuing VIDIOC_STREAMON on an output plane. You can change the intra-refresh period dynamically during the session, and this feature is applicable only to an encoder session.

Table: Control IDs for intra-refresh

Control ID for H.264 and HEVC codecs	Accepted format	Range
`V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD_TYPE`	enum `v4l2_mpeg_video_intra_refresh_period_type`	Random mode: `V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD_TYPE_RANDOM` Cyclic mode: `V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD_TYPE_CYCLIC`
`V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD`	Integer	Set the intra-refresh period to be less than an I-frame interval Unit: number of frames

The following code sample shows the static configuration to activate the random intra-refresh for every 10 frames:

v4l2_control control;
int ret = 0;
v4l2_mpeg_video_intra_refresh_period_type refreshtype = V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD_TYPE_RANDOM;

memset(&control, 0, sizeof(control));
control.id = V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD_TYPE;
control.value = refreshtype;
ret = ioctl(mDriverFd, VIDIOC_S_CTRL, &control);// mDriverFd returned from open() system call
if (ret) {
    return -1;
}
memset(&control, 0, sizeof(control));
control.id = V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD;
control.value = 10;
ret = ioctl(mDriverFd, VIDIOC_S_CTRL, &control);// mDriverFd returned from open() system call
if (ret) {
    return -1;
}

Rotation You can configure the VPU driver to rotate the input frame before encoding using the VIDIOC_S_CTRL ioctl system call. Set the rotation configuration before the VIDIOC_STREAMON on an output plane. The rotation feature doesn’t support dynamic configuration and is applicable only to an encoder session.

Table: Control IDs for rotation

Control ID for H.264 and HEVC codecs	Accepted format	Range
`V4L2_CID_ROTATE`	Integer	Unit: degrees

The following code sample shows the static configuration for rotating an input frame to 90 degrees:

v4l2_control control;
int ret = 0;
memset(&control, 0, sizeof(control));
control.id = V4L2_CID_ROTATE;
control.value = 90;
ret = ioctl(mDriverFd, VIDIOC_S_CTRL, &control);// mDriverFd returned from open() system call
if (ret) {
    return -1;
}

Frame QP range You can configure the VPU driver to set the minimum and maximum frame QP range parameters for I-frames, P-frames, and B-Frames to an intended value for encoded frames using the VIDIOC_S_CTRL ioctl system call. Set the frame QP range configuration before the VIDIOC_STREAMON on an output plane. The values are valid for an entire session. Dynamic configuration isn’t supported, and the frame QP feature is applicable only to an encoder session.

Table: Control IDs for frame QP range

Control ID for H.264 codecs	Accepted format	Range
`V4L2_CID_MPEG_VIDEO_H264_I_FRAME_MIN_QP`	Integer	Example according to the codec standard: 1 to 51 for 8-bit
`V4L2_CID_MPEG_VIDEO_H264_I_FRAME_MAX_QP`
`V4L2_CID_MPEG_VIDEO_H264_P_FRAME_MIN_QP`
`V4L2_CID_MPEG_VIDEO_H264_P_FRAME_MAX_QP`
`V4L2_CID_MPEG_VIDEO_H264_B_FRAME_MIN_QP`
`V4L2_CID_MPEG_VIDEO_H264_B_FRAME_MAX_QP`
`V4L2_CID_MPEG_VIDEO_HEVC_I_FRAME_MIN_QP`
`V4L2_CID_MPEG_VIDEO_HEVC_I_FRAME_MAX_QP`
`V4L2_CID_MPEG_VIDEO_HEVC_P_FRAME_MIN_QP`
`V4L2_CID_MPEG_VIDEO_HEVC_P_FRAME_MAX_QP`
`V4L2_CID_MPEG_VIDEO_HEVC_B_FRAME_MIN_QP`
`V4L2_CID_MPEG_VIDEO_HEVC_B_FRAME_MAX_QP`

The following code sample shows the static configuration parameter to choose 40 as the maximum QP and 10 as the minimum QP for an I-Frame, P-Frame, and B-Frame in an H.264 session:

v4l2_control control;
int ret = 0;
memset(&control, 0, sizeof(control));
control.id = V4L2_CID_MPEG_VIDEO_H264_I_FRAME_MIN_QP;
control.value = 10;
ret = ioctl(mDriverFd, VIDIOC_S_CTRL, &control);// mDriverFd returned from open() system call
if (ret) {
    return -1;
}
memset(&control, 0, sizeof(control));
control.id = V4L2_CID_MPEG_VIDEO_H264_P_FRAME_MIN_QP;
control.value = 10;
ret = ioctl(mDriverFd, VIDIOC_S_CTRL, &control);// mDriverFd returned from open() system call
if (ret) {
    return -1;
}
memset(&control, 0, sizeof(control));
control.id = V4L2_CID_MPEG_VIDEO_H264_B_FRAME_MIN_QP;
control.value = 10;
ret = ioctl(mDriverFd, VIDIOC_S_CTRL, &control);// mDriverFd returned from open() system call
if (ret) {
    return -1;
}
memset(&control, 0, sizeof(control));
control.id = V4L2_CID_MPEG_VIDEO_H264_I_FRAME_MAX_QP;
control.value = 40;
ret = ioctl(mDriverFd, VIDIOC_S_CTRL, &control);// mDriverFd returned from open() system call
if (ret) {
    return -1;
}
memset(&control, 0, sizeof(control));
control.id = V4L2_CID_MPEG_VIDEO_H264_P_FRAME_MAX_QP;
control.value = 40;
ret = ioctl(mDriverFd, VIDIOC_S_CTRL, &control);// mDriverFd returned from open() system call
if (ret) {
    return -1;
}
memset(&control, 0, sizeof(control));
control.id = V4L2_CID_MPEG_VIDEO_H264_B_FRAME_MAX_QP;
control.value = 40;
ret = ioctl(mDriverFd, VIDIOC_S_CTRL, &control);// mDriverFd returned from open() system call
if (ret) {
    return -1;
}

You can configure the following controls if you need to have the same minimum and maximum QP value for an I-Frame, P-Frame, and B-Frame: Table: Control IDs for H.264 codec

Table: Control IDs for H.264 codec

Control ID for H.264 codec	Accepted format	Range
`V4L2_CID_MPEG_VIDEO_H264_MIN_QP`	Integer	Example according to the code standard: 1 to 51 for 8-bit
`V4L2_CID_MPEG_VIDEO_H264_MAX_QP`	Integer	Example according to the code standard: 1 to 51 for 8-bit

Table: Control IDs for HEVC codec

Control ID for HEVC codec	Accepted format	Range
`V4L2_CID_MPEG_VIDEO_HEVC_MIN_QP`	Integer	Example according to the code standard: 1 to 51 for 8-bit
`V4L2_CID_MPEG_VIDEO_HEVC_MAX_QP`	Integer	Example according to the code standard: 1 to 51 for 8-bit

​GStreamer samples

​V4L2 samples

​Configure GStreamer and V4L2 APIs

​GStreamer APIs

​Configure GStreamer APIs

​V4L2 APIs

​VPU driver nodes

​V4L2 file operations

​V4L2 common commands for decoder and encoder

​V4L2 video decoder

​V4L2 video encoder

​Configure V4L2 APIs

​Next steps