Video Decoder Channel Start and File Seek Latency Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing video decoding technologies face challenges in accurately decoding video content when reference pictures are partially or completely unavailable, leading to issues like macroblocking and corruption during channel changes or file seeks in digital media playback.
Innovation Solution
The implementation of tuning parameters and methods to manage reference pictures, such as generating display order data, using substitute frame identifiers, and predicting picture order counts, allows for efficient decoding and display of video content even when reference pictures are unavailable, by selecting a start location for decoding and managing reference picture buffers effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If video decoding starts immediately after channel start or file seek operation, then latency is reduced, but decoding accuracy deteriorates due to unavailable reference pictures causing macroblocking and corruption
Solution Approach 1:
The system performs preliminary actions by searching for a suitable start picture (preferably an I-picture) before beginning decoding, and by pre-managing reference picture buffers to ensure they are properly initialized. This preliminary preparation prevents decoding errors while minimizing the delay before video display begins.
Solution Approach 2:
The system dynamically adjusts the start location based on the type of picture found at the seek location. If an I-picture is available, decoding starts immediately; if not, the system searches forward to find the next suitable picture. This dynamic adaptation optimizes both latency and decoding accuracy based on actual stream conditions.
2Manufacturing precision
If the system searches for a picture without inter-coded content to ensure accurate decoding, then decoding accuracy is improved, but the time to begin displaying video increases
Solution Approach 1:
The system performs a limited search for a suitable start picture rather than searching the entire stream. It examines a reasonable number of pictures ahead to find an I-picture or suitable start point, balancing the effort of searching with the need to begin playback promptly. This partial action avoids excessive delay while still improving decoding accuracy.
3Reliability
If reference picture buffers are managed to prevent corruption, then video quality is improved, but the complexity of the decoding system increases
Solution Approach 1:
The system extracts and manages only the necessary reference pictures for the current decoding context. By clearing the reference picture buffer of invalid pictures and retaining only those needed for accurate decoding, the system ensures video quality without maintaining unnecessary complexity in buffer management.
Solution Approach 2:
The system changes the state of reference picture buffers based on the decoding context - clearing buffers when reference pictures are unavailable and populating them when valid references exist. This dynamic parameter management ensures video quality while keeping the buffer management logic adaptable and relatively simple.
Data Source
AI summary
A video bit stream with pictures comprising inter-coded content can be decoded upon receiving a channel start or file seek instruction. Pictures for beginning decoding and display of the bit stream can be selected based at least in part on one or more tuning parameters that set a preference between a latency of beginning to display video and possible defects in the displayed video. In some embodiments, to implement decoding upon a channel start or file seek, one or more types of data are generated for one or more pictures. For example, picture order counts are generated for pictures after a channel start or file seek operation. As another example, a decoder generates a frame number value that triggers re-initialization of a reference picture buffer before decoding after a channel start or file seek operation.