Hello, lately I've been experimenting with Theora 1.1 and I've written a small program that reads some frames from ppm (or pgm or pgmyuv) files and encode them in a Theora/Ogg stream. Now, Theora encoder requests uncompressed YCbCr frames and lets you choose the pixel format among three format: 1) 444 (no chroma decimation, the Cb and Cr chroma planes are full width and full height) 2) 422 (chroma decimation by 2 in the X direction, the Cb and Cr chroma planes are half the width of the luma plane, but full height) 3) 420 (chroma decimation by 2 in both the X and Y directions, the Cb and Cr chroma planes are half the width and half the height of the luma plane) I have encoded black&white images (using only Y component, Cb=Cr=128) and color images (using all three components) in both 444 and 420 format, and then I have tested the output file with MPlayer. These are the results: 1) 420 B&W OK 2) 420 COLOR OK 3) 444 B&W OK 4) 444 COLOR NO So I'm having problems when Mplayer plays color 444 files. It may be my fault, a bug somewhere in my program, but before I make other tests I was wondering if MPlayer can read Theora-encoded YCbCr444 files. Here are two samples: http://mywing.altervista.org/mplayer/otheo444.ogg http://mywing.altervista.org/mplayer/otheo420.ogg (basically, what I did is: read the frame, converted it from RGB 24bit to YCbCr444, passed it to the encoder, and repeated that 100 times.) Thank you. Giorgio Vazzana
