[ONEM-41937] Fix sample DTS to prevent deletion of preexisting samples #528
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…s when PTS doesn't conflict - see original description from WebKit/WebKit#57363 below - this also reverts commit 90c814d (disable MP4 edit-lists suppost [EXPERIMENTAL][MSE] Fix sample DTS to prevent deletion of preexisting samples when PTS doesn't conflict Let's consider a preexisting samples A, B, C, and a new sample N with the following timestamps: Decoding time Presentation time ------------- ----------------- Sample A: 827.826164000 827.826164000 Sample B: 827.826164100 827.826164100 Sample C: 827.826164200 827.826164200 Sample N: 827.826125000 827.909542000 These disparities in DTS vs. PTS offsets between samples A and B exist because both samples come from completely different videos (eg: because of ad insertion). In a timeline: DTS ···NABC······· PTS ····ABC···N··· Judging by PTS, the samples A, B, C should remain and theoretically don't need to be erased. However, considering DTS, the samples A, B, C have to be erased, because the sample N would reach the video decoder earlier (by decoding ordering) and change the state of the decoder, making it unsuitable for samples A, B, C. This commit tries to fix the situation by changing sample N (the new sample) DTS to a value slightly higher than sample C DTS, like this: Decoding time Presentation time ------------- ----------------- Sample A: 827.826164000 827.826164000 Sample B: 827.826164100 827.826164100 Sample C: 827.826164200 827.826164200 Sample N: *827.826164201* 827.909542000 DTS ····ABCN······ PTS ····ABC···N··· This fix avoids the deletion of samples A, B, C and the potential problems associated with that.
volodymyr-ogorodnik-red
requested review from
amol-virnodkar-infosys and
pradeep-raveendranpillai-infosys
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[EXPERIMENTAL][MSE] Fix sample DTS to prevent deletion of preexisting samples when PTS doesn't conflict
Let's consider a preexisting samples A, B, C, and a new sample N with the following timestamps:
Sample A: 827.826164000 827.826164000
Sample B: 827.826164100 827.826164100
Sample C: 827.826164200 827.826164200
Sample N: 827.826125000 827.909542000
These disparities in DTS vs. PTS offsets between samples A and B exist because both samples come from completely different videos (eg: because of ad insertion).
In a timeline:
DTS ···NABC·······
PTS ····ABC···N···
Judging by PTS, the samples A, B, C should remain and theoretically don't need to be erased. However, considering DTS, the samples A, B, C have to be erased, because the sample N would reach the video decoder earlier (by decoding ordering) and change the state of the decoder, making it unsuitable for samples A, B, C.
This commit tries to fix the situation by changing sample N (the new sample) DTS to a value slightly higher than sample C DTS, like this:
Sample A: 827.826164000 827.826164000
Sample B: 827.826164100 827.826164100
Sample C: 827.826164200 827.826164200
Sample N: 827.826164201 827.909542000
DTS ····ABCN······
PTS ····ABC···N···
This fix avoids the deletion of samples A, B, C and the potential problems associated with that.
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