| amr-orig.txt | amr-changed.txt | |||
|---|---|---|---|---|
| CMR (4 bits): Indicates a codec mode request sent to the speech | CMR (4 bits): Indicates a codec mode request sent to the speech | |||
| encoder at the site of the receiver of this payload. The value of | encoder at the site of the receiver of this payload. The value of | |||
| the CMR field is set to the frame type index of the corresponding | the CMR field is set to the frame type index of the corresponding | |||
| speech mode being requested. The frame type index may be 0-7 for | speech mode being requested. The frame type index may be 0-7 for | |||
| AMR, as defined in Table 1a in [2], or 0-8 for AMR-WB, as defined | AMR, as defined in Table 1a in [2], or 0-8 for AMR-WB, as defined | |||
| in Table 1a in [4]. CMR value 15 indicates that no mode request | in Table 1a in [4]. CMR value 15 indicates that the receiver has | |||
| is present, and other values are for future use. | no preference in which mode within the negotiated mode set to | |||
| receive, and other values are for future use. | ||||
| The codec mode request received in the CMR field is valid until the | The codec mode request received in the CMR field is valid until the | |||
| next codec mode request is received, i.e., a newly received CMR value | next codec mode request is received, i.e., a newly received CMR value | |||
| corresponding to a speech mode, or NO_DATA overrides the previously | corresponding to a speech mode, or CMR=15 overrides the previously | |||
| received CMR value corresponding to a speech mode or NO_DATA. | received CMR value corresponding to a speech mode or CMR=15. | |||
| Therefore, if a terminal continuously wishes to receive frames in the | Therefore, if a terminal continuously wishes to receive frames not | |||
| same mode X, it needs to set CMR=X for all its outbound payloads, and | higher than mode X, it needs to set CMR=X for all its outbound | |||
| if a terminal has no preference in which mode to receive, it SHOULD | payloads, and if a terminal has no preference in which mode within | |||
| set CMR=15 in all its outbound payloads. | the negotiated mode set to receive, it SHOULD set CMR=15 in all its | |||
| outbound payloads. | ||||
| If receiving a payload with a CMR value that is not a speech mode or | If receiving a payload with a CMR value that is not a speech mode or | |||
| NO_DATA, the CMR MUST be ignored by the receiver. | CMR=15, the CMR MUST be ignored by the receiver. | |||
| The encoder SHOULD follow a received codec mode request, but MAY | The encoder MUST follow a received codec mode request as soon as | |||
| change to a lower-numbered mode if it so chooses, for example, to | possible. It SHOULD use the requested mode, but MAY change to a | |||
| control congestion. | lower-numbered mode if it so chooses, for example, to | |||
| control congestion. However, the encoder MUST NOT use a | ||||
| higher-numbered mode than the received codec mode request. | ||||
| mode-set: Restricts the active codec mode set to a subset of all | mode-set: Restricts the active codec mode set to a subset of all | |||
| modes, for example, to be able to support transport | modes, for example, to be able to support transport | |||
| channels such as GSM networks in gateway use cases. | channels such as GSM networks in gateway use cases. | |||
| Possible values are a comma separated list of modes from | Possible values are a comma separated list of modes from | |||
| the set: 0,...,7 (see Table 1a [2]). The SID frame type | the set: 0,...,7 (see Table 1a [2]). The SID frame type | |||
| 8 and NO_DATA (frame type 15) are never included in the | 8 and NO_DATA (frame type 15) are never included in the | |||
| mode set, but can always be used. If mode-set is | mode set, but can always be used. If mode-set is | |||
| specified, it MUST be abided, and frames encoded with | specified, it MUST be abided, i.e. frames encoded with | |||
| modes outside of the subset MUST NOT be sent in any RTP | modes outside of the subset MUST NOT be sent in any RTP | |||
| payload or used in codec mode requests. If not present, | payload and codec mode requests MUST only use modes | |||
| all codec modes are allowed for the payload type. | within the mode-set or CMR=15. If the mode-set parameter | |||
| is not present, then all codec modes are allowed for the | ||||
| payload type. | ||||
| End of changes. 6 change blocks. | ||||
| 13 lines changed or deleted | 17 lines changed or added | |||
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