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| #### 9.10 Remaining Frame Header Data (Non-Key Frame) {#h-09-10} |
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| | Index | Description |
| | --------- | ----------------------------------------------------- |
| | `L(1)` | `mb_no_skip_coeff`. This flag indicates at the frame level if skipping of macroblocks with no non-zero coefficients is enabled. If it is set to `0`, then `prob_skip_false` is not read and `mb_skip_coeff` is forced to `0` for all macroblocks (see Sections 11.1 and 12.1). |
| | `L(8)` | `prob_skip_false` = probability used for decoding a macroblock-level flag, which indicates if a macroblock has any non-zero coefficients. Only read if `mb_no_skip_coeff` is `1`. |
| | `L(8)` | `prob_intra` = probability that a macroblock is "intra" predicted (that is, predicted from the already-encoded portions of the current frame), as opposed to "inter" predicted (that is, predicted from the contents of a prior frame). |
| | `L(8)` | `prob_last` = probability that an inter-predicted macroblock is predicted from the immediately previous frame, as opposed to the most recent golden frame or altref frame. |
| | `L(8)` | `prob_gf` = probability that an inter-predicted macroblock is predicted from the most recent golden frame, as opposed to the altref frame. |
| | `F` | If true, followed by four `L(8)`s updating the probabilities for the different types of intra-prediction for the Y plane. These probabilities correspond to the four interior nodes of the decoding tree for intra-Y modes in an interframe, that is, the even positions in the `ymode_tree` array given above. |
| | `F` | If true, followed by three `L(8)`s updating the probabilities for the different types of intra-prediction for the chroma planes. These probabilities correspond to the even positions in the `uv_mode_tree` array given above. |
| | `X` | Motion vector probability update. Details are given in Section 17.2, "Probability Updates". |
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| Decoding of this portion of the frame header is handled in the |
| reference decoder file `dixie.c` (Section 20.4). |
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