AMD AMF H.264 Codec Settings in XMedia Recode: Tips and Techniques

The AMD AMF H.264 (Advanced Media Framework) is a software API (Application Programming Interface) developed by AMD to enable hardware acceleration for video processing, specifically for the H.264 video format.

AMD AMF leverages AMD's GPU hardware to accelerate video encoding and decoding. This reduces the load on the CPU and optimizes performance, which is especially important in real-time video processing.

AMF H.264 also provides features that allow you to control video quality and make adjustments to the bitrate to achieve the best possible balance between quality and performance.

Mode

• Convert (convert video stream)
• Copy (copy video stream)

Codec

Determines which video codec to use for encoding.

Language

Sets the language that displays when playing the player.

FourCC

Is a 4-byte identifier which specifies the format of a video stream.

Delay(ms)

Sets the delay of the video stream.

Positive values start the stream later.

Negative values start the stream earlier.

Framerate

Sets the frame rate in frames per second.

Level

The level setting sets the limit for various parameters such as the maximum resolution, the maximum bitrate and the number of reference frames that can be used in an encode.

Higher levels require more powerful hardware, both for encoding and decoding.

Profil

The H.264 codec profile settings allow you to adjust the compression and quality. There are several profiles, each with different features and capabilities

• Baseline
• Main
• High

Preset

The preset setting controls the ratio of speed and quality of video encoding

• Speed: Prioritizes encoding speed and ensures that encoding is as fast as possible
• Balanced: Provides a good balance between encoding speed and the quality of the final video
• Quality: Prioritizes image quality, suitable for scenarios where the best video quality is required but at the expense of speed

Keyframe Interval

A GOP is an interval from I-frame to I-frame

Very high GOP lengths result in slightly more efficient compression.

Display mode

Progressive: must be set if the source material is progressive or is converted to progressive by a deinterlace filter.

Interlaced TFF (Top field first): must be set if the source material is Interlaced TFF
Interlaced BFF (Bottom field first): must be set if the source material is Interlaced BFF.

Color mode

Specify output colorspace format.

Number of reference frames

Specifies the number of images that are searched for similarities. Values from 4 to 5 are useful.
A maximum of 16 is possible.
The larger the value, the more time is required for compression.

Coding Type

• Auto.
• CABAC (Context Adaptive Binary Arithmetic Coding) is a specific coding method. Instead of variable length bit sequences, it uses a better arithmetic coding that brings between 10 and 20% savings in the data rate.
• CAVLC (Context Adaptive Variable Length Coding) is an efficient coding technique that offers good compression with low computational effort by adapting the code word lengths to the context of the data

CAVLC is less complex than CABAC. CABAC offers better compression, but also requires more computation.