MPEG-4 AVC/H.264 Video Codecs Comparison

The main goal of this report is the presentation of a comparative evaluation of the quality of new H.264 codecs using objective measures of assessment. The comparison was done using settings provided by the developers of each codec. The main task of the comparison is to analyze different H.264 encoders for the task of transcoding video—e.g., compressing video for personal use. Speed requirements are given for a sufficiently fast PC; fast presets are analogous to real-time encoding for a typical home-use PC.

Overall Conclusions
Overall, the leader in this comparison is x264, followed by DivX H.264, Elecard and MainConcept. The DiscretePhoton encoder demonstrates the worst results among all codecs tested.

Average bitrate ratio for a fixed quality for all categories and all presets (Y-SSIM)

The overall ranking of the codecs tested in this comparison is as follows:

          1. x264
          2. DivX H.264
          3. Elecard
          4. MainConcept
          5. XviD
          6. DiscretePhoton
          • MSE encoder
          • WebM encoder

WebM and Microsoft Expression encoders could not be placed in this list because of their longer encoding time compared with other encoders. The leader in this comparison is x264. Its quality difference (according to the SSIM metric) could be explained by the special encoding option ("tune-SSIM").

The difference between the Elecard and DivX H.264 encoders is almost nothing, and between these encoders and MainConcept is not overly significant, so these encoders tied for second and third in this comparison. This rank is based only on the encoders’ quality results. Encoding speed is not considered here.

x264 settings

Codec Conclusions

DiscretePhoton - one of the fastest encoder for this comparison, but because of its speed the encoding quality was not very good.

DivX H.264 - one of comparison leaders, quite balanced encoder with not very big number of parameters, this fact could be comfortable for users. This encoder is designed as a free sample application for DivX Plus HD compliant video encoding, and is a feature-constrained, for-purpose application.

Elecard - one of comparison leaders, codec with good encoding quality and very flexible settings. Many adjustable encoding settings are provided.

Microsoft Expression Encoder - encoder with good encoding quality but due to the fact of long initial loading time, the encoding time for Microsoft Expression Encoder is significantly higher than for other encoders.

MainConcept - good balanced encoder; has many encoding settings that can be adjusted. The results for “Movie” use-case was second, so this codec has a good potential to be one of comparison leaders.

x264 - one of the best codecs by encoding quality; has very user-friendly predefined presets, as well as many adjustable encoding settings.

XviD - an MPEG-4 ASP codec; its quality could be very close to or even higher than that of some commercial H.264 standard implementations, especially for encoding “Movie” sequences, but not for “HDTV” sequences.

WebM - good new non H.264 encoder, it shows good quality but due to the low encoding speed it is not presented in encoders list by quality.

Source: MSU Video Group