Motion picture decoding method, motion picture decoding device, and electronic apparatus

A motion picture decoding method for decoding an encoded motion picture on each of a plurality of channels and synthesizing and reproducing the motion pictures on the same screen, comprising the steps of:

• obtaining structure information of the encoded motion picture on each channel;
• determining display targets to be reproduced, the display targets being frames at the same time on the channels, when a predetermined special playback mode is designated;
• determining a delayed channel for the display targets based on the structure information, the delayed channel being a channel for which it is predicted that decoding of the corresponding display target will be last completed;
• and
• decoding the display targets, and after the frame on the delayed channel is completely decoded, synthesizing and reproducing the decoded image data on the channels at the same timing,
• wherein, in the delayed channel determining step, of frames as the display targets, a frame having a largest required-for-decoding number of frames is obtained, the required-for-decoding number of frames being the number of frames required for decoding and being obtained based on the structure information, and the channel of the frame having the largest required-for-decoding number of frames is determined as the delayed channel.

A motion picture decoding device for decoding an encoded motion picture on each of a plurality of channels and synthesizing and reproducing the motion pictures on the same screen, comprising:

• a decoder configured to decode the encoded motion picture on each channel and obtain structure information of the encoded motion picture on each channel;
• a plurality of frame memories configured to store frame image data output from the decoder for the respective channels;
• and
• a controller configured to control the decoder and each of the frame memories and receive the structure information from the decoder,
• wherein the controller performs the processes of:
• determining display targets to be reproduced, the display targets being frames at the same time on the channels, based on the structure information, when a predetermined special playback mode is designated;
• and
• instructing the decoder to decode the display targets, and
• in the display target determining process, frames at the same time on the channels having an evaluation index larger than or equal to a predetermined threshold are excluded from the display targets, the evaluation index being based on a difference in a required-for-decoding number of frames between each channel, the required-for-decoding number of frames being the number of frames required for decoding and being calculated based on the structure information.

A motion picture decoding device for decoding an encoded motion picture on each of a plurality of channels and synthesizing and reproducing the motion pictures on the same screen, comprising:

• a decoder configured to decode the encoded motion picture on each channel and obtaining structure information of the encoded motion picture on each channel;
• a plurality of frame memories configured to store frame image data output from the decoder for the respective channels;
• and
• a controller configured to control the decoder and each of the frame memories and receive the structure information from the decoder,
• wherein the controller performs the processes of:
• determining display targets to be reproduced, the display targets being frames at the same time on the channels, when a predetermined special playback mode is designated;
• determining a delayed channel for the display targets based on the structure information, the delayed channel being a channel for which it is predicted that decoding will be the last;
• and
• instructing the decoder to decode the display targets, and after the frame on the delayed channel is completely decoded, instructing the frame memories to synthesize and reproduce the decoded image data on the respective channels at the same timing,
• wherein, in the delayed channel determining process, of frames as the display targets, a frame having a largest required-for-decoding number of frames is obtained, the required-for-decoding number of frames being the number of frames required for decoding and being obtained based on the structure information, and the channel of the frame having the largest required-for-decoding number of frames is determined as the delayed channel.