Fast spatial Direct mode decision for B slice based on temporal information in H.264 standard

Jin, Xiaocong; Huang, Yiqing; Liu, Qin; Wu, Shuijiong; Ikenaga, Takeshi

doi:10.1109/ispacs.2009.5383833

Cited by 2 publications

(5 citation statements)

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“…However, the overall time saving using the scheme in [3] is quite good and shows an average improvement of 19% for B slices. The approach in [5] shows better results than that in [3] at low QP values, but at the cost of increased memory size. The direction filtering in [9] improves the encoding speed by about 16% for B slices and shows a total improvement of 11%.…”

Section: Resultsmentioning

confidence: 98%

“…To this end, execution cycles for 50 frames are measured using the ED mode decision in [2], [3], and [5], the direction filtering in [9], and the proposed CDF scheme. For comparison, previous works in [3] and [5] are implemented in the H.264 encoder described in Section III whereas previous works in [2] and [9] are subsets of the proposed CDF scheme. The encoding speeds of those five schemes are compared to the speed obtained without any of these schemes and the results are shown in Table VII.…”

Section: Resultsmentioning

confidence: 99%

“…The R-D performances of the ED mode decision in [3] and [5], the direction filtering in [9], and the proposed CDF are now compared. The scheme in [2] is excluded from this comparison because the probability of an ED mode decision is very small, thus there would be a negligible change in R-D performance.…”

Section: Resultsmentioning

confidence: 99%

“…In the high QP values set, the QP values are 28, 32, 36, and 40 for P slices and 30, 34, 38, and 42 for B slices. The BDBR and BDPSNR in [3] and [5] are very small in the low QP values set compared to those in high QP values set because the number of MBs which are encoded by the ED mode decision is very small with low QP values as shown in Table VIII. Since many MBs are coded in the direct mode by the early mode decision scheme in the case of high QP values, the BDBRs of the schemes in [3] and [5] increase substantially.…”

Section: Resultsmentioning

confidence: 99%

“…The algorithm in [4] initially computes the direct mode for all MBs and then determines whether the best mode is the direct mode for each MB based on the peak signal-to-noise ratio (PSNR) of a frame. In [2] and [5], the ED mode decision is determined based on the temporal correlation between the current and the reference frames. Many other works have been conducted on the ED mode decision [6]- [8].…”

mentioning

confidence: 99%

See 4 more Smart Citations

Cascaded Direction Filtering for Fast Multidirectional Inter-Prediction in H.264/AVC Main and High Profile Compression

Rhee

Kim

Lee

2012

IEEE Trans. Circuits Syst. Video Technol.

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Early direct mode decision is a popular technique to improve the execution speed of inter-predictions in a B slice. However, the improvement is limited when this technique is applied to a hardware-based pipelined architecture or to the video sequences where the ratio of macroblocks (MBs) encoded as the direct mode is low. This paper proposes a novel fast interprediction algorithm for B slices which increases the encoding speed by early decision of the direction of the inter-prediction using spatial and temporal correlation in a video. A speed-up is achieved by selecting a prediction direction with a lower complexity and discarding a prediction direction with a higher complexity. For the case when early mode decision is not possible, additional speed-up is achieved by partially skipping unidirectional motion estimation (ME) if the estimated cost of the ME is greater than the result of the direct mode prediction that is completed much faster than ME. This proposed sequence of early decisions is referred to as cascaded direction filtering (CDF). The proposed algorithm increases the early mode decision rate, which improves the encoding speed effectively for a hardware-based pipelined architecture as well as videos with a low ratio of MBs encoded as the direct mode. The additional memory size and bandwidth overhead required for the proposed CDF are very small. Experimental results show that the proposed CDF scheme improves the encoding speed by 45% for B slices and 32% for overall sequences. The bitrate is increased by less than 1% with a small peak signal-to-noise ratio degradation of 0.03 dB on average. Index Terms-Cascaded direction filtering, direction filtering, early direct mode decision, H.264/AVC encoder, high profile, main profile.

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