Video encoding

A method comprising:

• determining, by a first processing core, a first preliminary quantization parameter (QP) for a first row of coding tree units (CTUs) in a frame of a video;
• encoding, by the first processing core, the first row of CTUs in the frame of the video to produce first encoded CTUs, wherein a CTU in the first row of CTUs is encoded with a QP equal to the first preliminary QP;
• determining, by a second processing core, a second preliminary QP for a second row of CTUs of the frame of the video, prior to encoding any CTUs in the second row of CTUs;
• setting, by the second processing core, a running QP to the first preliminary QP for the first row of CTUs, prior to the first processing core encoding a last CTU in the first row of CTUs;
• and
• encoding, by the second processing core, the second row of CTUs using the running QP, to produce second encoded CTUs.

A non-transitory computer readable storage medium storing a first program for execution by a first processing core and storing a second program for execution by a second processing core, the first program including first instructions to cause the first processing core to:

• determine a first preliminary Quantization Parameter (QP) for a first row of Coding Tree Units (CTUs) of a video frame;
• and
• encode the first row of CTUs in the video frame to produce first encoded CTUs, wherein a CTU in the first row of CTUs is encoded with a QP equal to the first preliminary QP;
• wherein the second program includes second instructions to cause the second processing core to:
• determine a second preliminary QP for a second row of CTUs of the video frame, prior to encoding any CTUs in the second row of CTUs;
• set a running QP for the second row of CTUs to the first preliminary QP for the first row of CTUs;
• and
• encode the second row of CTUs using the running QP, to produce second encoded CTUs, the running QP being inherited by skip-blocks in the second row of CTUs.