View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0000138 | JVT JM H.264/AVC reference software | encoder | public | 2008-10-06 18:11 | 2008-10-09 07:25 |
| Reporter | Fadi Boulos | Assigned To | |||
| Priority | normal | Severity | minor | Reproducibility | always |
| Status | new | Resolution | open | ||
| Product Version | JM-14.0 | ||||
| Summary | 0000138: Closed GOPs do not restrict prediction from previous GOPs | ||||
| Description | After losing some I slices from an Annex B .264 bitstream, the temporal error propagates to next GOPs although EnableOpenGOP is disabled. | ||||
| Additional Information | Attached is the encoding configuration file. | ||||
| Tags | No tags attached. | ||||
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2008-10-06 18:11
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Your configuration file has "EnableOpenGOP" set to 0. Did you enable this flag and you are just sending a basic file, or not? |
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I did not enable this flag. The bitstream I encoded exceeds the 2MB upload limit. If you need it, tell me where to send it. |
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OpenGOPs are only supported when you enable this flag. Please enable it. In the coming version we will also have support for the Random Access SEI message, but this should work fine for you now. Note that EnableIDRGOP combined with IDRPeriod can also provide some flexibility in terms of GOP structures. |
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My understanding is that when I disable the "EnableOpenGOP" flag, the temporal error should not propagate to subsequent GOPs. But it is propagating in my case. On the other hand, using an IDRPeriod of 8 with "EnableIDRGOP" set to 1 is not working fine. The decoded video has 296 whereas the original video had 322. Moreover, if I use Motion Copy concealment, the decoder crashes. |
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I just realized that you were using field coding. Please see the manual that stated the following: 4.2.5 EnableOpenGOP Class: Numeric (Integer) Description: Enables support for Open GOP encodes. Default is disabled (0). Note: Parameter currently does not support field coding, while it enforces reference reordering if hierarchical encoding is used. Furthermore, given that you are using EnableIDRGOP, that means that you need to increment the number of coded pictures since that mode forces periodic GOPs without the presence of B coded pictures prior to an IDR. Also, given that your coding is field based, I would think that it is likely that any error concealment is not supported (I am not familiar with this code so cannot comment more on this). |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2008-10-06 18:11 | Fadi Boulos | New Issue | |
| 2008-10-06 18:11 | Fadi Boulos | File Added: encoder_above_marathon_high_closedI.cfg | |
| 2008-10-06 18:26 | Alexis Michael Tourapis | Note Added: 0000243 | |
| 2008-10-06 18:31 | Fadi Boulos | Note Added: 0000244 | |
| 2008-10-06 23:18 | Alexis Michael Tourapis | Note Added: 0000245 | |
| 2008-10-07 15:07 | Fadi Boulos | Note Added: 0000246 | |
| 2008-10-09 07:25 | Alexis Michael Tourapis | Note Added: 0000247 |
