Signal clipping protection using pre-existing audio gain metadata

摘要

The application describes a method and an apparatus to prevent clipping of an audio signal when protection against signal clipping by received audio metadata is not guaranteed. The method may be used to prevent clipping for the case of downmixing a multichannel signal to a stereo audio signal. According to the method, it is determined whether first gain values (4) based on received audio metadata are sufficient for protection against clipping of the audio signal. The audio metadata is embedded in a first audio stream (1). In case a first gain value (4) is not sufficient for protection, the respective first gain value (4) is replaced with a gain value sufficient for protection against clipping of the audio signal. Preferably, in case no metadata related to dynamic range control is present in the first audio stream (1), the method may add gain values sufficient for protection against signal clipping.

主权项

1. A method of providing protection against signal clipping of an audio signal derived from digital audio data, the method comprising:
determining whether first gain values based on received audio metadata are sufficient for protection against clipping of the audio signal, the received audio metadata embedded in a first digital audio stream; and in case a first gain value is not sufficient, replacing the respective first gain value with a gain value sufficient for protection against clipping of the audio signal, wherein the step of determining comprises the steps of: computing second gain values based on the digital audio data, the second gain values sufficient for clipping protection of the audio signal; comparing the first gain values based on the received audio metadata and the computed second gain values; and selecting a minimum of a first gain value and a corresponding second gain value based on comparing the first gain values and the computed second gain values.