Reproduction device, reproduction method, and program for stereoscopic reproduction
In performing stereoscopic view, a shift information memory stores, as a number of pixel lengths, an offset indicating how far in a right direction or a left direction to move coordinates of pixels to realize stereoscopic view. When realizing stereoscopic view, a plane shift engine moves the coordinates of image data in a graphics plane in the right direction or the left direction by the number of pixel lengths indicated by the offset. When a scale of video data targeted for stereoscopic view is changed by a basic graphics plane, a shift distance of pixel coordinates by the plane shift engine is based on a number of pixel lengths obtained by multiplying the offset by a changed scaling factor in the horizontal direction.
1. A playback apparatus that realizes stereoscopic playback comprising:
a video decoder operable to obtain video frames by decoding a video stream;
a plane memory that stores graphics subtitle data at a predetermined resolution defined by a number of horizontal and vertical pixels;
an offset storage that stores an offset indicating a base number of pixels by which pixels coordinates of the graphics subtitle data are to be shifted in each of a right and left direction in order to realize stereoscopic playback;
a shift engine operable to shift respective coordinates of the pixels making up the graphics subtitle data in the plane memory by the offset in a horizontal direction; and
a compositor that composites graphics subtitle data in which the coordinates of the pixels have been shifted with the video frames, wherein
a shift distance by which the shift engine shifts the pixel coordinates is based on a value obtained by multiplying the offset by a scaling factor when a video scale is modified during the stereoscopic playback.
2. The playback apparatus of claim 1 wherein
when the scaling factor is less than 1,
the shift distance is a number of pixel lengths obtained by multiplying the offset by the scaling factor and rounding up any numerical value after a decimal point thereof.
3. The playback apparatus of claim 1 wherein
the shift distance obtained by the multiplication is a shift distance D(N) when N frames have passed since a generation of a scaling instruction, and
a shift distance D(i), that is a shift distance when i frames have passed after the generation of the scaling instruction (i ≦N), is calculated according to the following expression:
shift distance D ( i )=(Offset−(Factor×Offset))×( i/N )
Offset: number of pixel lengths indicated by the offset
Factor: scaling factor.
4. The playback apparatus of claim 1 wherein
the plane memory is a graphics plane storing graphics subtitle data,
the playback apparatus further includes a video plane that is a plane memory storing therein the video frames obtained by decoding,
the shift engine, when scaling is performed on the video frames in the video plane, shifts the graphics subtitle data stored in the graphics plane and the coordinates of the pixels included in the video frames, and
when the plane shift engine shifts the pixels of the video frames in the video plane, a relative value of the shift distance of the pixels in the video plane and the shift distance of the pixels in the graphics plane is a value based on a number of pixel lengths obtained by multiplying the offset by the changed scaling factor.
5. The playback apparatus of claim 4 wherein
a plane offset V of coordinates of image data in the video plane is calculated according to the following expression:
coordinate plane offset V=D (Factor× D )
D: Offset in the graphics plane
Factor: scaling factor.
6. A playback method for realizing stereoscopic playback on a computer, comprising:
obtaining video frames by decoding a video stream;
writing graphics subtitle data at a predetermined resolution defined by a number of horizontal and vertical pixels in a plane memory in the computer;
acquiring an offset indicating a base number of pixels by which pixel coordinates of the graphics subtitle data are to be shifted in each of a right and left direction in order to realize stereoscopic playback;
shifting respective coordinates of the pixels making up the graphics subtitle data in the plane memory by the offset in each of a right and left direction; and
compositing graphics subtitle data in which the coordinates of the pixels have been shifted with the video frames obtained by the decoding, wherein
a shift distance by which the shifting shifts the pixel coordinates is based on a value obtained by multiplying the offset by the scaling factor when a video scale is modified during the stereoscopic playback.
7. A non-transitory recording medium on which a program is recorded for realizing stereoscopic playback on a computer, comprising:
obtaining video frames by decoding a video stream;
writing graphics subtitle data at a predetermined resolution defined by a predetermined number of horizontal and vertical pixels in a plane memory in the computer;
acquiring an offset indicating a base number of pixels by which pixel coordinates of the graphics subtitle data are to be shifted in each of a right and a left direction in order to realizes stereoscopic playback;
shifting respective coordinates of the pixels making up the graphics subtitle data in the plane memory by the offset in a horizontal direction, and
compositing graphics subtitle data in which the coordinates of the pixels have been shifted with the video frames obtained by the decoding, wherein
a shift distance by which the shifting shifts the pixel coordinates is based on a value obtained by multiplying the offset by the scaling factor when a video scale is modified during the stereoscopic playback.