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Current Result Document :
ÇѱÛÁ¦¸ñ(Korean Title) |
H.264/AVC¸¦ À§ÇÑ Ãʱâ Quantization Parameter °áÁ¤ ¾Ë°í¸®Áò |
¿µ¹®Á¦¸ñ(English Title) |
The First Quantization Parameter Decision Algorithm for the H.264/AVC Encoder |
ÀúÀÚ(Author) |
±Ç¼ø¿µ
ÀÌ»óÇå
À̵¿ÇÏ
Soonyoung Kwon
Sangheon Lee
Dongha Lee
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¿ø¹®¼ö·Ïó(Citation) |
VOL 35 NO. 03 PP. 0235 ~ 0242 (2008. 06) |
Çѱ۳»¿ë (Korean Abstract) |
µ¿¿µ»ó ¾ÐÃà Ç¥ÁØÀÎ H.264/AVC´Â ¾ÐÃà È¿À²À» ³ôÀ̱â À§Çؼ ±âÁ¸ÀÇ Ç¥ÁØ°ú´Â ´Ù¸¥ ÀûÀÀÀûÀÎ ºñÆ®À² Á¦¾î(Adaptive Rate Control) ±â¹ýÀ» Á¦°øÇÑ´Ù. ÇÏÁö¸¸ µ¿¿µ»óÀÇ Ã¹ ÇÁ·¹ÀÓ¿¡ ´ëÇÑ QP¸¦ Á¤È®È÷ ¿¹ÃøÇÏÁö ¸øÇÏ´Â ¹®Á¦Á¡À» º¸ÀδÙ. ºÎÈ£È ÀÔ·Â º¯¼ö Áß ÀϺΠ°ªÀ» ÀÌ¿ëÇؼ 3~4°³ÀÇ Æ¯Á¤ »ó¼ö °ª Áß¿¡ Çϳª¸¦ ¼±ÅÃÇÏ¿© Ãʱâ QP °ªÀ» Á¤ÇÏ°Ô µÈ´Ù. ÀÌ·¸°Ô ±¸ÇØÁø Ãʱâ QP°ªÀº ½ÇÁ¦ ºÎÈ£È µÇ¾úÀ» ¶§ÀÇ ºñÆ®¾çÀ» °í·ÁÇÏÁö ¾ÊÀº ¹æ¹ýÀ̶ó¼ ƯÁ¤ ¿µ»ó¿¡¼´Â ºñÆ®À² Á¦¾î¿¡ ½ÇÆÐÇϰųª ÈÁúÀÌ ±Þ°ÝÇÏ°Ô º¯ÇÏ´Â ¸ð½ÀµéÀ» º¸¿©ÁØ´Ù. º» ³í¹®¿¡¼´Â H.264/AVC ºÎȣȱ⿡¼ ù ¹ø° ÇÁ·¹ÀÓÀÇ QP°ªÀ» °áÁ¤ÇÏ´Â »õ·Î¿î ¾Ë°í¸®ÁòÀ» Á¦¾ÈÇÑ´Ù. Á¦¾ÈµÈ ¾Ë°í¸®ÁòÀº ±âÁ¸ÀÇ ¹æ¹ý¿¡ µû¶ó Ãʱâ QP¸¦ °áÁ¤Çؼ ºÎȣȸ¦ ¼öÇàÇÑ ÈÄ »ý¼ºµÇ´Â ºñÆ®¾ç¿¡ µû¶ó¼ »õ·Î¿î Ãʱâ QP °ªÀ» ±¸ÇÑ´Ù. »ý¼ºµÇ´Â ºñÆ®¾ç°ú »õ·Î¿î Ãʱâ QP °ª »çÀÌ¿¡´Â ¼±Çü °ü°è(A linear QP prediction model)°¡ ¼º¸³ÇϹǷΠÃÖÀû¿¡ °¡±î¿î Ãʱâ QP°ªÀ» ¿¹Ãø ÇÒ ¼ö ÀÖ´Ù. ÀÌ·¸°Ô ±¸ÇØÁø »õ·Î¿î Ãʱâ QP°ªÀ» ÀÌ¿ëÇؼ ù ÇÁ·¹ÀÓÀ» ÀçºÎÈ£È ÇÑ´Ù. ½ÇÇè°á°ú ±âÁ¸ ¾Ë°í¸®ÁòÀ¸·Î´Â ºñÆ®À² Á¦¾î°¡ ºÒ°¡´É Çß´ø ¿µ»óÀ» È¿À²ÀûÀ¸·Î ºñÆ®À² Á¦¾î¸¦ ÇÏ¿´°í ±âÁ¸ÀÇ ¹æ¹ýº¸´Ù Æò±Õ PSNRÀÇ Çâ»óÀ» È®ÀÎÇÏ¿´´Ù. È¸é »çÀÌÀÇ ÈÁú º¯È ÆøÀ» ÁÙÀÓÀ¸·Î½á ÁÖ°üÀûÀÎ ÈÁú ¶ÇÇÑ Çâ»óÇÏ¿´´Ù. |
¿µ¹®³»¿ë (English Abstract) |
To improve video quality and coding efficiency, H.264/AVC adopted an adaptive rate control. But this method has a problem as it cannot predict an accurate quantization parameter (QP) for the first frame. The first QP is decided among four constant values by using encoder input parameters. It does not consider encoding bits, results in significant fluctuation of the image quality and decreases the average quality of the whole coded sequence. In this paper, we propose a new algorithm for the first frame QP decision in the H.264/AVC encoder. The QP is decided by the existing algorithm and the first frame is encoded. According to the encoded bits, the new initial QP is decided. We can predict optimal value because there is a linear relationship between encoded bits and the new initial QP. Next, we re-encode the first frame using the new initial QP. Experimental results show that the proposed algorithm not only achieves better quality than the state of the art algorithm, but also adopts a rate control forthe sequence that was impossible with the existing algorithm. By reducing fluctuation, subjective quality also improved. |
Å°¿öµå(Keyword) |
H.264/AVC ºÎȣȱâ
Ãʱâ QP
ºñÆ®À² Á¦¾î
¼±Çü QP ¿¹Ãø ¸ðµ¨
H.264/AVC Encoder
initial QP
rate control
and a linear QP prediction model
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