> ## Documentation Index > Fetch the complete documentation index at: https://dragonwingdocs.qualcomm.com/llms.txt > Use this file to discover all available pages before exploring further. # Advanced video specifications For more information on the video decode and encode capabilities such as the supported profiles, levels, resolutions, frame rates, bit rates, and limitations, select the following tabs:

{/* Table 2: Feature Descriptions */}

Table: Adreno VPU feature description for QCS6490

Feature	Description	Codecs	Remarks
Encoder input color formats	NV12 and QC08C	H.264 and HEVC	None
Decoder output color formats	NV12, QC08C, and QC10C	H.264, HEVC, and VP9	QC10C is supported only on `qcom-multimedia-proprietary-image`
Rotation	Supports 90, 180, and 270-degree rotation before encoding the frame	H.264 and HEVC	Supports static rotation only
Flip	Supports horizontal and vertical flip before encoding the frame	H.264 and HEVC	Supports static and dynamic flip. Flip is supported only on `qcom-multimedia-proprietary-image`
B-Frame encode	Up to 1920 × 1088 at 60 fps encode	H.264 and HEVC	The maximum number of B-Frames supported between two P-Frames is one and is supported only on `qcom-multimedia-proprietary-image`
Hierarchical-P encode	Up to 5 layers	H.264 and HEVC	Hierarchical-P encode is supported only on `qcom-multimedia-proprietary-image`
Initial QP override	Supports I-Frames, P-Frames, and B-Frames	H.264 and HEVC	Initial QP override is supported only on `qcom-multimedia-proprietary-image`
Slice encode	Yes	H.264 and HEVC	The number of bits per slice or the number of macroblocks per slice determines the slice boundary support. Slice is supported only on `qcom-multimedia-proprietary-image`
Intra-refresh	Random refresh mode	H.264 and HEVC	Supported only in 8-bit encoding Supported only in the CBR RC mode Intra-refresh is supported only on `qcom-multimedia-proprietary-image`
Rate control	CBR, VBR, and MBR	H.264 and HEVC	Rate control is supported only on `qcom-multimedia-proprietary-image`
LTR	2 frames	H.264 and HEVC	Supported in CBR RC mode and only on `qcom-multimedia-proprietary-image`
Dynamic properties for encoder	Sync frame, bit rate, and fps	H.264 and HEVC	Supported in CBR and VBR RC modes and only on `qcom-multimedia-proprietary-image`

Note: End-to-end functionality using [Qualcomm IM SDK](https://dragonwingdocs.qualcomm.com/SDKs/IMSDK) is validated up to 3840 × 2160 resolution.

{/* Table 3: Decoder Capabilities */}

Table: Adreno VPU decoder capabilities for QCS6490

Decoder Standard	Supported Profile and Level	Minimum/Maximum resolution, Maximum frame rate, and bit rate	Maximum supported resolution, frame rate, and bit rate	Limitations
HEVC	Main profile 8-bit up to level 5.1 Main profile 10-bit, up to level 5.1, HLG schemes	Minimum resolution: 96 x 96 Maximum resolution: 4096 x 2160 or 2160x4096 Maximum frame rate: 480 fps Maximum bit rate: 100 Mbps	1280 x 720 at 480 fps, 100 Mbps 1920 x 1088 at 240 fps, 100 Mbps 3840 x 2160 at 60 fps, 100 Mbps 4096 x 2169 at 60 fps, 100 Mbps	Maximum 128 slices per frame Individual slice-based decoding
H.264	Constrained baseline, baseline, main, high, constrained high profiles; up to level 5.2	Minimum resolution: 96 × 96 Maximum resolution: 4096 × 2160 or 2160 × 4096 Maximum framerate: 480 fps Maximum bitrate: 100 Mbps	1280 × 720 at 480 fps, 100 Mbps 1920 × 1088 at 240 fps, 100 Mbps 3840 × 2160 at 60 fps, 100 Mbps 4096 × 2160 at 60 fps, 100 Mbps	Flexible macroblock order (FMO) Arbitrary slice ordering (ASO) Redundant slices (RS) Data partition Maximum 10 slices per frame Interlaced content isn't supported
VP9	Profile 0; 8-bit up to level 5.1 Profile 2; 10-bit up to level 5.1, HLG/PQ schemes	Minimum resolution: 96 × 96 Maximum resolution: 4096 × 2160 or 2160 × 4096 Maximum framerate: 480 fps Maximum bitrate: 100 Mbps	1280 × 720 at 480 fps, 100 Mbps 1920 × 1088 at 240 fps, 100 Mbps 3840 × 2160 at 60 fps, 100 Mbps 4096 × 2160 at 60 fps, 100 Mbps	Profile 2; 12-bit isn't supported

{/* Table 4: Encoder Capabilities */}

Table: Adreno VPU encoder capabilities for QCS6490

Encoder standard	Supported profile and level and RC modes	Minimum/Maximum resolution, maximum frame rate, and maximum bit rate	Supported resolution, frame rate, bit rate	Limitations
H.264	Constrained baseline, baseline, main, high, constrained high profiles; up to level 5 VBR, CBR, MBR	Minimum resolution: 128 × 128 Maximum resolution: 4096 × 2160 or 2160 × 4096 Maximum framerate: 240 fps Maximum bitrate: 100 Mbps	1280 × 720 at 240 fps, 100 Mbps 1920 × 1088 at 120 fps, 100 Mbps 3840 × 2160 at 30 fps, 100 Mbps 4096 × 2160 at 30 fps, 100 Mbps	None
HEVC	Main profile 8-bit, up to level 5.0 Main/High tier VBR, CBR, MBR	Minimum resolution: 128 × 128 Maximum resolution: 4096 × 2160 or 2160 × 4096 Maximum framerate: 240 fps Maximum bitrate: 100 Mbps	1280 × 720 at 240 fps, 100 Mbps 1920 × 1088 at 120 fps, 100 Mbps 3840 × 2160 at 30 fps, 100 Mbps 4096 × 2160 at 30 fps, 100 Mbps	Vertical tiling is only enabled for frame width 960

{/* Table 2: Feature Descriptions */}

Table: Adreno VPU feature description for Dragonwing IQ-8275

Feature	Description	Codecs	Limitations
Encoder input color formats	NV12 and QC08C	H.264 and HEVC	None
Decoder output color formats	NV12, QC08C, and QC10C	H.264, HEVC, VP9 and AV1	QC10C is supported only on `qcom-multimedia-proprietary-image`
B-Frame encode	Up to 1920 × 1088 at 120 fps encode	H.264 and HEVC	The maximum number of B-Frames supported between two P-Frames is one. B-Frame is supported only on `qcom-multimedia-proprietary-image`
Initial QP override	Supports I-Frames, P-Frames, and B-Frames	H.264 and HEVC	None
Rate control	CBR and VBR	H.264 and HEVC	None
Dynamic properties for encoder	Sync frame, bit rate, and fps	H.264 and HEVC	Supported in CBR and VBR RC modes. Dynamic properties are supported only on `qcom-multimedia-proprietary-image`

Note: End-to-end functionality using [Qualcomm IM SDK](https://dragonwingdocs.qualcomm.com/SDKs/IMSDK). is validated up to 3840 × 2160 resolution.

{/* Table 3: Decoder Capabilities */}

Table: Adreno VPU decoder capabilities for Dragonwing IQ-8275

Decoder standard	Supported profile and level	Minimum/Maximum resolution, maximum frame rate, and maximum bit rate	Maximum supported resolution, frame rate, and bit rate	Limitations
HEVC	Main profile 8-bit, up to level 5.1 Main tier, high tier Main10, profile up to level 5.1 Main/High tier, HLG schemes	Minimum resolution: 96 × 96 Maximum resolution: 4096 × 2160 or 2160 × 4096 Maximum frame rate: 480 fps Maximum bit rate: 160 Mbps	1280 × 720 at 480 fps, 160 Mbps (IBP/IPP) 1920 × 1088 at 480 fps, 160 Mbps (IBP/IPP) 3840 × 2160 at 120 fps, 160 Mbps (IBP/IPP) 4096 × 2160 at 60 fps, 120 Mbps (IBP/IPP)	Individual slice-based decoding
H.264	Constrained baseline, Baseline, main, high, constrained high profiles; up to level 5.2	Minimum resolution: 96 × 96 Maximum resolution: 4096 × 2160 or 2160 × 4096 Maximum frame rate: 480 fps Maximum bit rate: 160 Mbps	1280 × 720 at 480 fps, 160 Mbps (IBP/IPP) 1920 × 1088 at 480 fps, 160 Mbps (IBP/IPP) 3840 × 2160 at 120 fps, 160 Mbps (IBP/IPP) 4096 × 2160 at 60 fps, 120 Mbps (IBP/IPP)	Flexible macroblock order (FMO) Arbitrary slice ordering (ASO) Redundant slices (RS) Data partition Individual slice-based decoding Non-progressive-only content up to 1920 × 1088 Best effort B-Frame decode is: 3840 × 2160 at 120 fps
VP9	Profile 0; 8-bit, up to level 5.1 Profile2, 10-bit, up to level 5.1, HLG/PQ schemes	Minimum resolution: 96 × 96 Maximum resolution: 4096 × 2160 or 2160 × 4096 Maximum frame rate: 120 fps Maximum bit rate: 50 Mbps	1280 × 720 at 120 fps, 50 Mbps 1920 × 1088 at 120 fps, 50 Mbps 3840 × 2160 at 120 fps, 50 Mbps 4096 × 2160 at 60 fps, 50 Mbps	Profile 2, 12-bit isn't supported Individual slice-based decoding
AV1	Main (Profile-0) Maximum level: 5.1 HLG/PQ schemes	Minimum resolution: 96 × 96 Maximum resolution: 4096 × 2160 or 2160 × 4096 Maximum frame rate: 240 fps Maximum bit rate: 120 Mbps	1280 × 720 at 240 fps, 120 Mbps 1920 × 1088 at 240 fps, 120 Mbps 3840 × 2160 at 60 fps, 120 Mbps 4096 × 2160 at 60 fps, 120 Mbps	Individual slice-based decoding

{/* Table 4: Encoder Capabilities */}

Table: Adreno VPU encoder capabilities for Dragonwing IQ-8275

Encoder standard	Supported profile, level, and RC mode	Minimum/Maximum resolution, maximum frame rate, and maximum bit rate	Maximum supported resolution, frame rate, and bit rate	Limitations
H.264	Constrained baseline, baseline, main, high, constrained high profiles; up to level 5.2 VBR and CBR	Minimum resolution: 128 × 128 Maximum resolution: 4096 × 2160 or 2160 × 4096 Maximum frame rate: 480 fps Maximum bit rate: 160 Mbps Maximum operating rate: 480	1280 × 720 at 480 fps, 88 Mbps 1920 × 1088 at 240 fps, 128 Mbps 3840 × 2160 at 60 fps, 80 Mbps 4096 × 2160 at 60 fps, 92 Mbps	None
HEVC	Main profile 8-bit, up to level 5.1 Main/High tier VBR and CBR	Minimum resolution: 96 × 96 Maximum resolution: 4096 × 2160 or 2160 × 4096 Maximum frame rate: 480 fps Maximum bit rate: 160 Mbps Maximum operating rate: 480 Maximum frame rate: 480 fps Maximum bit rate: 160 Mbps	1280 × 720 at 480 fps, 62 Mbps 1920 × 1088 at 240 fps, 90 Mbps 3840 × 2160 at 60 fps, 56 Mbps 4096 × 2160 at 60 fps, 64 Mbps	Multislice is enabled

{/* Table: Feature Descriptions */}

Table: Adreno VPU feature description for Dragonwing IQ-9075

Feature	Description	Codecs	Limitations
Encoder input color formats	NV12 and QC08C	H.264 and HEVC	None
Decoder output color formats	NV12, QC08C, and QC10C	H.264, HEVC, VP9 and AV1	QC10C is supported only on `qcom-multimedia-proprietary-image`
B-Frame encode	Up to 3840 × 2160 at 60 fps encode	H.264 and HEVC	The maximum number of B-Frames supported between two P-Frames is one. B-Frame encode is supported only on `qcom-multimedia-proprietary-image`
Initial QP override	Supports for I-Frames, P-Frames, and B-Frames	H.264 and HEVC	None
Rate control	CBR and VBR	H.264 and HEVC	None
Dynamic properties for encoder	Sync frame, bit rate, and fps	H.264 and HEVC	Supported in CBR and VBR RC modes. Dynamic properties are supported only on `qcom-multimedia-proprietary-image`

Note: End-to-end functionality using [Qualcomm IM SDK](https://dragonwingdocs.qualcomm.com/SDKs/IMSDK) is validated up to 3840 × 2160 resolution.

{/* Table: Decoder Capabilities IQ-9075 */}

Table: Adreno VPU decoder capabilities for Dragonwing IQ-9075

Decoder standard	Supported profile and level	Minimum/maximum resolution, Maximum frame rate, and bit rate	Maximum supported resolution, frame rate, and bit rate	Limitations
HEVC	Main profile 8-bit, up to level 6.2, main tier, high tier Main10 profile up to level 6.2 Main/High tier HLG schemes	Minimum resolution: 96 × 96 Maximum resolution: 8192 × 4320 or 4320 × 8192 Maximum frame rate: 480 fps Maximum bit rate: 160 Mbps	1280 × 720 at 480 fps, 160 Mbps (IBP/IPP) 1920 × 1088 at 480 fps, 160 Mbps (IBP/IPP) 3840 × 2160 at 240 fps, 80 Mbps (IBP/IPP) 3840 × 2160 at 120 fps, 160 Mbps (IBP/IPP) 4096 × 2160 at 120 fps, 80 Mbps (IBP/IPP) 7680 × 4320 at 30 fps, 120 Mbps (IBP/IPP) 7680 × 4320 at 60 fps, 80 Mbps (IBP/IPP) 8192 × 4320 at 30 fps, 120 Mbps (IBP/IPP) 8192 × 4320 at 48 fps, 80 Mbps (IBP/IPP)	Individual slice-based decoding
H.264	Constrained baseline, baseline, main, high, constrained high profiles; up to level 6.1	Minimum resolution: 96 × 96 Maximum resolution: 8192 × 4320 or 4320 × 8192 Maximum frame rate: 480 fps Maximum bit rate: 220 Mbps (CAVLC), 160 Mbps (CABAC)	1280 × 720 at 480 fps, 160 Mbps (IBP/IPP) 1920 × 1088 at 480 fps, 160 Mbps (IBP/IPP) 3840 × 2160 at 240 fps, 80 Mbps (IPP) 3840 × 2160 at 120 fps, 160 Mbps (IBP/IPP) 4096 × 2160 at 120 fps, 80 Mbps (IPP) 7680 × 4320 at 60 fps, 80 Mbps (IPP) 7680 × 4320 at 30 fps, 120 Mbps (IBP/IPP) 8192 × 4320 at 30 fps, 120 Mbps (IPP) 8192 × 4320 at 48 fps, 80 Mbps (IPP)	Flexible macroblock order (FMO) Arbitrary slice ordering (ASO) Redundant slices (RS) Data partition Individual slice-based decoding Non-progressive-only content up to 1920 × 1088 Best effort B-Frame decodes are: 3840 × 2160 at 240 fps 4096 × 2160 at 120 fps 7680 × 4320 at 60 fps 8192 × 4320 at 30/48 fps
VP9	Profile 0; 8-bit up to level 5.1 Profile2, 10-bit, up to level 5.1, HLG/PQ schemes	Minimum resolution: 96 × 96 Maximum resolution: 4096 × 2304 or 2304 × 4096 Maximum frame rate: 120 fps Maximum bit rate: 100 Mbps	1280 × 720 at 120 fps, 100 Mbps 1920 × 1088 at 120 fps, 100 Mbps 3840 × 2160 at 60 fps, 100 Mbps 3840 × 2160 at 240 fps, 30 Mbps 4096 × 2160 at 60 fps, 100 Mbps 4096 × 2304 at 60 fps, 100 Mbps	Profile 2, 12-bit isn't supported
AV1	Main (Profile-0), 8-bit and 10-bit Maximum level: 6.1 HLG/PQ schemes	Minimum resolution: 96 × 96 Maximum resolution: 8192 × 4320 or 4320 × 8192 Maximum frame rate: 480 fps Maximum bit rate: 120 Mbps	1280 × 720 at 480 fps, 120 Mbps 1920 × 1088 at 480 fps, 120 Mbps 3840 × 2160 at 240 fps, 120 Mbps 3840 × 2160 at 120 fps, 120 Mbps 4096 × 2160 at 120 fps, 120 Mbps 7680 × 4320 at 30 fps, 120 Mbps 7680 × 4320 at 60 fps, 120 Mbps 8192 × 4320 at 30 fps, 120 Mbps 8192 × 4320 at 48 fps, 120 Mbps	Individual slice-based decoding

{/* Table: Decoder Capabilities IQ-9075 */}

Table: Adreno VPU decoder capabilities for Dragonwing IQ-9075

Encoder standard	Supported profile, level, and RC modes	Minimum/Maximum resolution, maximum frame rate, and maximum bit rate	Supported resolution, frame rate, bit rate	Limitations
H.264	Constrained baseline, baseline, main, high, constrained high profiles; up to level 6.0 VBR and CBR	Minimum resolution: 128 × 128 Maximum resolution: 8192 × 4320 or 4320 × 8192 Maximum frame rate: 480 fps Maximum bit rate: 220 Mbps (CAVLC), 160 Mbps (CABAC)	1280 × 720 at 480 fps, 160 Mbps 1920 × 1088 at 480 fps, 160 Mbps 3840 × 2160 at 120 fps, 160 Mbps 7680 × 4320 at 30 fps, 160 Mbps	Individual encoded slice delivery per buffer
HEVC	Main profile 8-bit, up to level 6.0, 6.1, Main/High tier VBR and CBR	Minimum resolution: 96 × 96 Maximum resolution: 8192 × 4320 or 4320 × 8192 Maximum frame rate: 480 fps Maximum bit rate: 160 Mbps	1280 × 720 at 480 fps, 160 Mbps 1920 × 1088 at 480 fps, 160 Mbps 3840 × 2160 at 120 fps, 160 Mbps 7680 × 4320 at 30 fps, 160 Mbps	Individual encoded slice delivery per buffer Multislice is enabled

{/* Table: Feature Descriptions */}

Table: Adreno VPU feature description for QCS615

Feature	Description	Codecs	Limitations
Encoder input color formats	NV12	H.264 and HEVC	None
Decoder output color formats	NV12 and QC08C	H.264, HEVC, and VP9	None
Hierarchical-P encode	Up to 5 layers	H.264 and HEVC	None
Initial QP override	Supports for I-Frames, P-Frames, and B-Frames	H.264 and HEVC	None
Rate control	CBR and VBR	H.264 and HEVC	None
Dynamic properties for encoder	Sync frame	H.264 and HEVC	None

{/* Table: Decoder Capabilities QCS615 */}

Table: Adreno VPU decoder capabilities for QCS615

Decoder standard	Supported profile and level	Minimum/Maximum resolution, maximum frame rate, and maximum bit rate	Maximum supported resolution, frame rate, and bit rate	Limitations
HEVC	Main profile 8-bit, up to level 6	Minimum resolution: 96 × 96 Maximum resolution: 3840 × 2160 or 2160 × 3840 Maximum frame rate: 240 fps Maximum bit rate: 100 Mbps	1280 × 720 at 240 fps, 100 Mbps 1920 × 1088 at 120 fps, 100 Mbps 3840 × 2160 at 30 fps, 100 Mbps	Individual slice-based decoding
H.264	Constrained baseline, baseline, main, high Constrained high profiles; up to level 5.2	Minimum resolution: 96 × 96 Maximum resolution: 3840 × 2160 or 2160 × 3840 Maximum frame rate: 240 fps Maximum bit rate: 100 Mbps	1280 × 720 at 240 fps, 100 Mbps 1920 × 1088 at 120 fps, 100 Mbps 3840 × 2160 at 30 fps, 100 Mbps	Flexible macroblock order (FMO) Arbitrary slice ordering (ASO) Redundant slices (RS) Data partition Individual slice-based decoding Interlaced content is not supported
VP9	Profile 0; 8-bit up to level 5.1	Minimum resolution: 96 × 96 Maximum resolution: 3840 × 2160 or 2160 × 3840 Maximum frame rate: 240 fps Maximum bit rate: 100 Mbps	1280 × 720 at 240 fps, 100 Mbps 1920 × 1088 at 120 fps, 100 Mbps 3840 × 2160 at 30 fps, 100 Mbps	None

{/* Table: Encoder Capabilities QCS615 */}

Table: Adreno VPU encoder capabilities for QCS615

Encoder standard	Supported profile, level, and RC modes	Minimum/Maximum resolution, maximum frame rate, and maximum bit rate	Supported resolution, frame rate, bit rate	Limitations
H.264	Constrained baseline, baseline, main, high, constrained high profiles; up to level 5.2 VBR and CBR	Minimum resolution: 96 × 96 Maximum resolution: 3840 × 2160 or 2160 × 3840 Maximum frame rate: 240 fps Maximum bit rate: 100 Mbps	1280 × 720 at 240 fps, 100 Mbps 1920 × 1088 at 120 fps, 100 Mbps 3840 × 2160 at 30 fps, 100 Mbps	None
HEVC	Main profile 8-bit, up to level 6.0, Main/High tier VBR and CBR	Minimum resolution: 96 × 96 Maximum resolution: 3840 × 2160 or 2160 × 3840 Maximum frame rate: 240 fps Maximum bit rate: 100 Mbps	1280 × 720 at 240 fps, 100 Mbps 1920 × 1088 at 120 fps, 100 Mbps 3840 × 2160 at 30 fps, 100 Mbps	None

## **Feature descriptions** The supported encoder feature descriptions are as follows: **B-Frame encode** B-Frame uses both the earlier and the future frames as reference data to obtain the highest amount of data compression. The Adreno VPU encodes frames with adaptive B type to obtain the highest possible compression without compromising video quality. **Encoder initial QP override** Video encoding compresses signal levels by mapping them to discrete values. Quantization is a lossy process, and the levels of quantization govern the quality compared to compression. Encoders start with a default Quantization Parameter (QP) at the beginning. Based on the configured bit rate and scene complexity, encoders determine the right QP value by continuously monitoring the complexity and redundancy across frames. The encoder takes a few seconds to reach a steady state and predict the correct QP value that matches the target bit rate, also known as rate convergence. **Hierarchical-P encode** In the Hierarchical-P (Hier-P) feature, the encoder organizes the frames into many layers, with frames of one layer referencing frames only from the lower layers. The lowest layer, also known as layer 0 or the base layer, is the only exception. The following image shows the layer encoding pattern:

Figure: Hier-P layer encoding pattern

In the image, TL-0 represents the base layer, and the remaining layers represent the enhancement layers. Hier-P improves error resilience and temporal scalability. The Hier-P feature is useful for video telephony (VT) or videoconferencing applications that involve channel errors. Hier-P allows you to control error propagation by selectively dropping the enhancement layers. **Slice encode** Encoders can compress a frame with an independently decodable Group-of-blocks (GOB), also known as slices. If there is a data loss or corruption, each slice is independently decodable and intends to be a unit of recovery. The advantages of introducing slices in an encoded frame are: * Encoder ignores a corrupt slice and skips to the next slice, thus restricting the corruption to a part of the frame instead of the entire frame. * Encoder sizes the slices to fit them within a network packet to help with transmission. * Encoder retransmits erroneous slices instead of sending the entire frame. * Applications use slices to reduce latency in real-time communication. Applications transmit and decode slices in parallel, eliminating the need to wait for the entire frame to encode. Slices also work as resynchronization markers because the decoders can resume from the next slice (marker) when there are bit errors. The H.264 and HEVC encoders support slicing on Qualcomm Linux. The number of bits per slice or the number of macroblocks per slice is a slice boundary. **Intra-refresh** The intra-refresh feature reduces the channel loss in streaming and casting applications that favor a constant bit rate. The Adreno VPU supports random intra-refresh mode. **Video encoder preprocessing** Applications can use the Adreno VPU to rotate or flip a YUV frame before encoding it. The Adreno VPU rotates or flips the YUV frame without consuming extra power. **Rate control** The following table lists the supported rate control algorithms: **Table: Supported rate control algorithms**

Table: Supported rate control algorithms

Rate control mode	Description
Variable bit rate (VBR)	Minimizes the frame-by-frame video quality fluctuation Camcorder and Wi-Fi display are the example use cases
Constant bit rate (CBR)	Reduces bit rate fluctuation Used for real-time communication with channel bandwidth limitation Video telephony and streaming are the example use cases
Maximum bit rate (MBR)	Limits the bit rate while maintaining flexibility and may bounce up and down within the set target Bit rate increases when the activity in a scene increases within a maximum limit Integrated with a smart bit allocation (SBA) feature to achieve better quality at a lower bit rate

**Long-term reference (LTR) support** Video compression works by eliminating redundancies within the frame (intra-frame) and between the frames (inter-frame). Earlier, the encoded frames that used to serve as a basis to derive future frames were known as reference frames. The following reference frames allow advanced encoding applications to control the way a reference frame is stored and referred: * **Short-term reference (STR)**: The encoder maintains the recent frames in a reference buffer list from the newest to the oldest. The encoder automatically manages frames using STRs for reference, and deletes them from a stored list when they're no longer used. * **Long-term reference (LTR)**: Frames that the application can save, use, and remove. The LTR frames help improve quality and ensure error resiliency in video communication. The maximum number of frames that can be marked with LTR frames depends on the device capability. LTR frames are useful in error-prone channels. Referring to LTR in error-prone channels reduces the possibility of drift errors due to channel losses. The receiver must confirm that the LTR is received successfully and that it can request a new LTR when an error occurs. The network protocols have checksums that can confirm this behavior, along with the decoder corruption flags. New LTR frames are generated from the sender until the receiver confirms that a successful LTR is received. LTR frames are also useful in videos with scene changes where an LTR with the earlier scene is preserved. If that scene comes back, then the LTR can be used effectively. At the start of a new Group-of-pictures (GOP), the encoder automatically fills the LTR slots, with the first slot (slot number 0) containing an IDR frame. Applications can explicitly send an LTR mark request to mark the LTR frames in the appropriate slots. The following flow diagram shows LTR usage and how to mark and use LTR frames on an H.264 or HEVC encoder:

Figure: LTR encoding

**Dynamic encoder properties** The Adreno VPU encoder supports dynamic change of properties such as bit rate, frame rate, and sync frame. This support allows the application to change the properties and helps in improved visual experience, video data adjusting to network conditions, and minimizing the loss of data during transmission.