System and method of transmission and reception of progressive content with isolated fields for conversion to interlaced display
View Patent ↗Systems and methods of coding progressive content with isolated fields for conversion to interlaced display are provided. Some systems and methods may find use in, for example, digital video compression systems and methods. Film material may be encoded as video material with an intended field polarity and an explicit 3:2 pull-down operation for interlaced display (e.g., a 30-frames-per-second display).
1. A video decoder circuit comprising:
circuitry operable to decode encoded film material that has been encoded with a field polarity and a 3:2 pull-down operation, where the encoded film material comprises coded frames and inserted isolated coded fields;
wherein the circuitry is operable to present a video sequence for interlaced display, and
wherein the circuitry is operable to determine a decoding time or a presentation time for a particular picture based upon at least one decoding time stamp (DTS) or at least one presentation time stamp (PTS) for a previously decoded picture.
2. The video decoder circuit of claim 1 , wherein the circuitry is operable to derive timestamp information from presentation times of previous pictures and a frame rate or a field rate indicated in a video stream.
3. A video decoder circuit comprising:
circuitry operable to decode encoded film material that has been encoded with a field polarity and a 3:2 pull-down operation, where the encoded film material comprises coded frames and inserted isolated coded fields,
wherein the circuitry is operable to present a video sequence for interlaced display, and
wherein the circuitry is operable to determine a decoding timestamp for a particular picture of the encoded film material without knowledge of a film mode state of the particular picture.
4. The video decoder circuit of claim 3 , wherein the circuitry is operable to determine a presentation timestamp for a particular picture of the encoded film material without knowledge of a film mode state of the particular picture.
5. The video decoder circuit of claim 3 , wherein the encoded film material comprises a repeat-field flag, and the circuitry is operable to derive decoding and presentation times without using the repeat-field flag.
6. A method for decoding video information, the method comprising:
determining whether to use a 3:2 pull-down format; and
if a decoder determines to use the 3:2 pull-down format, decoding the encoded film material and presenting a video sequence without using a film mode flag, and
if the decoder determines not to use the 3:2 pull-down format, detecting and removing the inserted isolated coded fields from the encoded film material and presenting a video sequence for display.
7. The method of claim 6 , wherein if the decoder determines not to use the 3:2 pulldown format, detecting and removing the inserted isolated coded fields from the encoded film material when the decoder is communicatively coupled to a progressive display.
8. The method of claim 6 , wherein if the decoder determines not to use the 3:2 pulldown format, detecting and removing the inserted isolated coded fields from the encoded film material when the decoder is communicatively coupled to a display that has a first format or a first frame rate that is different from a second format or a second frame rate indicated in a received video bitstream.
9. The method of claim 6 , wherein if the decoder determines not to use the 3:2 pulldown format, detecting an inserted isolated coded field by predicting the inserted isolated coded field based on a previous frame.
10. The method of claim 6 , wherein if a decoder determines to use the 3:2 pull-down format, decoding the encoded film material and presenting a video sequence without using a film mode flag when the decoder is communicatively coupled to an interlaced display.
11. The method of claim 6 , where the encoded film material comprises film mode flags.
12. The method of claim 6 , wherein if a decoder determines to use the 3:2 pull-down format, the encoded film material comprises top_field_first and repeat_first_field flags and the video sequence is presented without using the top_field_first and repeat_first_field flags.
13. The method of claim 6 comprising determining a decoding timestamp for a particular picture without knowledge of a film mode state of the particular picture.
14. The method of claim 6 comprising determining a presentation timestamp for a particular picture without knowledge of a film mode state of the particular picture.
15. The method of claim 6 comprising determining field polarities of encoded frames based on polarities of the inserted isolated coded fields.