After much discussion on IRC, we've come up with some further clarifications to
the use of the output gain field and R128 tags.
In section 5.1:
Virtually all players and media frameworks should apply it by
- default. If a player chooses to apply any volume adjustment or
- gain modification, such as the R128_TRACK_GAIN, R128_ALBUM_GAIN
- (see Section 5.2) or a user-facing volume knob, the adjustment
- MUST be applied in addition to this output gain in order to
- achieve playback at the desired volume.
+ default. If a player chooses to apply any gain modification,
+ such as the R128_TRACK_GAIN or R128_ALBUM_GAIN (see Section 5.2),
+ the adjustment MUST be applied in addition to this output
+ gain in order to achieve playback at the normalised volume.
In section 5.2.1:
- If an encoder wishes to use R128 normalization, and the output gain
- is not otherwise constrained or specified, the encoder SHOULD write
- the R128 gain into the 'output gain' field and store a tag containing
- "R128_TRACK_GAIN=0". That is, it should assume that by default tools
+ The encoder should assume that by default tools
will respect the 'output gain' field, and not the comment tag. If a
tool modifies the ID header's 'output gain' field, it MUST also
update or remove the R128_TRACK_GAIN and R128_ALBUM_GAIN comment tags
--ian
_______________________________________________
codec mailing list
codec@ietf.org
https://www.ietf.org/mailman/listinfo/codec
