Picture coding apparatus
View Patent ↗A picture coding apparatus, optimizing a data amount of coded picture data without entailing an increase in circuit size and/or power consumption, includes a picture input unit obtaining a moving picture signal Vin. Further, the picture coding apparatus includes a buffer, includes a lead detecting unit detecting a lead portion from the moving picture represented by the moving picture signal Vin, includes a coding unit coding the moving picture signal Vin in the lead portion detected by the lead detecting unit, according to a coding condition for temporary coding, and includes a coding condition generating unit generating a coding condition for actual coding, based on the result of the coding by the coding unit and the coding condition for temporary coding. Additionally, coding unit codes the moving picture signal Vin representing the moving picture including the aforementioned lead portion, according to the coding condition for actual coding.
1. A picture coding apparatus for coding a moving picture signal, said picture coding apparatus comprising:
a moving picture obtaining unit configured to obtain the moving picture signal;
a lead detecting unit configured to detect a lead portion of the moving picture signal;
a first coding unit configured to perform actual coding of all of the obtained moving picture signal, so as to generate and output binary data, and configured to perform temporary coding of the detected lead portion of the moving picture signal extending up to the generation of the binary data;
a second coding unit configured to perform at least variable-length coding on the binary data output from said first coding unit, so as to output variable coded binary data; and
a coding condition generating unit configured to generate coding condition for the actual coding, the coding condition for the actual coding being generated based on a temporary coding condition used by said first coding unit to perform the temporary coding of the detected lead portion,
wherein said first coding unit performs the temporary coding of the detected lead portion using the temporary coding condition,
wherein said first coding unit performs the actual coding of all of the obtained moving picture signal according to the generated coding condition for the actual coding, so as to generate and output the binary data, and
wherein said second coding unit processes the binary data obtained according to the coding condition for the actual coding, so as to output the variable coded binary data.
2. The picture coding apparatus according to claim 1 ,
wherein said moving picture obtaining unit obtains the moving picture signal, which comprises a plurality of pictures, by sequentially obtaining each picture of the plurality of pictures,
wherein the lead portion of the moving picture signal includes lead pictures of the plurality of pictures, and
wherein said first coding unit temporarily codes the lead pictures included in the lead portion, in a period when the actual coding is not to be performed on the plurality of pictures obtained by said moving picture obtaining unit.
3. The picture coding apparatus according to claim 1 , wherein, in said first coding unit, a lead picture reference relationship, which is used in the temporary coding of a lead picture corresponding to the lead portion of the moving picture signal, is different from a lead picture reference relationship, which is used in the actual coding of the lead picture.
4. A picture coding method for coding a moving picture signal via a picture coding apparatus, said picture coding method comprising:
obtaining, via a moving picture obtaining unit, the moving picture signal;
detecting, via a lead detecting unit, a lead portion of the moving picture signal;
performing, via a first coding unit, temporary coding of the detected lead portion of the moving picture signal extending up to a generation of binary data, the temporary coding being performed on the detected lead portion using a temporary coding condition;
generating, via a coding condition generating unit, a coding condition for actual coding, the coding condition for the actual coding being based on the first coding condition used in said performing of the temporary coding of the detected lead portion;
performing, via the first coding unit, actual coding of all of the obtained moving picture signal according to the generated coding condition for the actual coding, so as to generate the binary data; and
performing, via a second coding unit, at least variable-length coding on the generated binary data, so as to output variable-length coded binary data.