Method for transcoding video streams with reduced number of predictions
View Patent ↗A first request and a second request are received from a first client terminal and a second client terminal respectively. In response to the first request and second request, a first set of predictions is generated by predicting macroblocks of frames of a video stream. In response to the first request, a first set of quantized transform coefficients is generated by transforming the first set of predictions, and a first coded video stream is generated by coding the first set of quantized transform coefficients. In response to the second request, a second set of quantized transform coefficients is generated by transforming the first set of predictions, and a second coded video stream is generated by coding the second set of quantized transform coefficients. Finally, the first coded video stream is transmitted to the first client terminal, and the second coded video stream is transmitted to the second client terminal.
1. A method for transcoding video streams by a server, comprising:
receiving a first request from a first client terminal;
receiving a second request from a second client terminal;
predicting macroblocks of frames of a first video stream to generate a first set of predictions in response to the first request and the second request;
transforming the first set of predictions into a first set of quantized transform coefficients in response to the first request;
transforming the first set of predictions into a second set of quantized transform coefficients in response to the second request;
coding the first set of quantized transform coefficients into a first coded video stream;
coding the second set of quantized transform coefficients into a second coded video stream having a resolution identical to a resolution of the first coded video stream;
transmitting the first coded video stream from the server to the first client terminal, and transmitting the second coded video stream from the server to the second client terminal;
receiving a third request from a third client terminal;
predicting macroblocks of frames of a second video stream to generate a second set of predictions in response to the third request, wherein the second video stream has a resolution different from a resolution of the first video stream;
transforming the second set of predictions into a third set of quantized transform coefficients;
coding the third set of quantized transform coefficients into a third coded video stream; and
transmitting the third coded video stream from the server to the third client terminal.
2. The method of claim 1 further comprising:
decoding a source video into an original video stream; and
scaling the original video stream into the first video stream.
3. The method of claim 1 further comprising:
decoding a source video into an original video stream; and
scaling the original video stream into the first video stream and the second video stream.
4. The method of claim 1 , wherein the first set of predictions comprises motion vectors, and predicting macroblocks of frames of the second video stream to generate the second set of predictions in response to the third request comprises:
using the motion vectors to predict the macroblocks of the frames of the second video stream to generate the second set of predictions.
5. The method of claim 4 , wherein the resolution of the second video stream is greater than the resolution of the first video stream.
6. The method of claim 1 further comprising:
receiving a fourth request from a fourth client terminal;
transforming the second set of predictions into a fourth set of quantized transform coefficients in response to the fourth request;
coding the fourth set of quantized transform coefficients into a fourth coded video stream having a resolution identical to a resolution of the third coded video stream; and
transmitting the fourth coded video stream from the server to the fourth client terminal.