Pros of FFmpeg

• Comprehensive multimedia framework supporting a wide range of formats and codecs
• Extensive documentation and large community support
• Actively maintained with frequent updates and improvements

Cons of FFmpeg

• Large codebase and complex architecture, potentially steeper learning curve
• Higher resource requirements due to its comprehensive nature
• May be overkill for projects only requiring H.265/HEVC functionality

Code Comparison

FFmpeg (libavcodec/hevc.c):

static int decode_nal_units(HEVCContext *s, const uint8_t *buf, int length)
{
    int i, consumed, ret = 0;

    s->ref = NULL;
    s->eos = 0;

libde265 (libde265/slice.cc):

bool slice_segment_header::read(bitreader* br, class decoder_context* ctx)
{
  first_slice_segment_in_pic_flag = get_bits(br,1);
  if (ctx->get_RapPicFlag()) {
    no_output_of_prior_pics_flag = get_bits(br,1);
  }

Both repositories focus on video coding, but FFmpeg is a more comprehensive multimedia framework, while libde265 specifically targets H.265/HEVC decoding. FFmpeg offers broader functionality but may be more complex, while libde265 provides a more focused solution for H.265 decoding.

Pros of libavif

• Supports the newer AV1 Image File Format (AVIF), which offers better compression and quality than HEVC
• More active development and community support
• Broader compatibility with modern web browsers and platforms

Cons of libavif

• Potentially slower encoding/decoding compared to libde265 due to AV1's complexity
• Higher computational requirements for optimal performance
• Less mature technology, may have more bugs or inconsistencies

Code Comparison

libavif:

avifResult avifEncoderWrite(avifEncoder * encoder, const avifImage * image, avifRWData * output)
{
    // Encoding logic for AVIF
}

libde265:

de265_error de265_encode_image(de265_encoder_context* ctx, const struct de265_image* img, int* more_data_to_come)
{
    // Encoding logic for HEVC
}

Both libraries provide similar encoding functions, but libavif is specifically designed for AVIF format, while libde265 focuses on HEVC encoding. The function signatures and parameters differ, reflecting the unique requirements of each format.

Pros of rav1e

• Written in Rust, offering memory safety and performance benefits
• Implements the more modern AV1 video codec, which provides better compression efficiency
• Active development with frequent updates and contributions

Cons of rav1e

• Potentially slower encoding speed compared to libde265's HEVC implementation
• Less mature and may have fewer tools and integrations available
• Larger file size due to the complexity of the AV1 codec

Code Comparison

rav1e (Rust):

let mut ctx: Context<u8> = Config::default()
    .with_threads(4)
    .with_encoder_config(EncoderConfig::default())
    .new_context()
    .unwrap();

libde265 (C):

de265_decoder_context* ctx = de265_new_decoder();
de265_error err = de265_start_worker_threads(ctx, 4);

Both examples show initialization of the encoder/decoder context with 4 threads, but rav1e's Rust implementation offers a more fluent and type-safe approach.

Pros of VMAF

• Focuses on video quality assessment, providing a perceptual quality metric
• Actively maintained by Netflix with regular updates and improvements
• Includes pre-trained models and tools for easy integration

Cons of VMAF

• More specialized, primarily for video quality measurement
• Requires more computational resources for analysis
• Less suitable for general-purpose video encoding/decoding tasks

Code Comparison

VMAF (Python):

import vmaf
model = vmaf.VmafModel()
score = model.compute_score(reference_video, distorted_video)

libde265 (C):

#include <libde265/de265.h>
de265_decoder_context* ctx = de265_new_decoder();
de265_push_data(ctx, data, data_size, 0);
de265_decode(ctx, &more);

Additional Notes

VMAF is tailored for video quality assessment, while libde265 is a HEVC/H.265 decoder library. VMAF provides tools for measuring perceived video quality, whereas libde265 focuses on efficient video decoding. The choice between them depends on the specific use case: VMAF for quality analysis, libde265 for HEVC decoding in applications or media players.