diff --git a/libavutil/samplefmt.h b/libavutil/samplefmt.h index 29a26f0b41..bb5ba5924a 100644 --- a/libavutil/samplefmt.h +++ b/libavutil/samplefmt.h @@ -22,7 +22,26 @@ #include "avutil.h" /** - * all in native-endian format + * Audio Sample Formats + * + * @par + * The data described by the sample format is always in native-endian order. + * Sample values can be expressed by native C types, hence the lack of a signed + * 24-bit sample format even though it is a common raw audio data format. + * + * @par + * The floating-point formats are based on full volume being in the range + * [-1.0, 1.0]. Any values outside this range are beyond full volume level. + * + * @par + * The data layout as used in av_samples_fill_arrays() and elsewhere in Libav + * (such as AVFrame in libavcodec) is as follows: + * + * For planar sample formats, each audio channel is in a separate data plane, + * and linesize is the buffer size, in bytes, for a single plane. All data + * planes must be the same size. For packed sample formats, only the first data + * plane is used, and samples for each channel are interleaved. In this case, + * linesize is the buffer size, in bytes, for the 1 plane. */ enum AVSampleFormat { AV_SAMPLE_FMT_NONE = -1, @@ -139,6 +158,9 @@ int av_samples_get_buffer_size(int *linesize, int nb_channels, int nb_samples, * buffer for planar layout, or the aligned size of the buffer for all channels * for packed layout. * + * @see enum AVSampleFormat + * The documentation for AVSampleFormat describes the data layout. + * * @param[out] audio_data array to be filled with the pointer for each channel * @param[out] linesize calculated linesize, may be NULL * @param buf the pointer to a buffer containing the samples @@ -157,6 +179,9 @@ int av_samples_fill_arrays(uint8_t **audio_data, int *linesize, uint8_t *buf, * linesize accordingly. * The allocated samples buffer can be freed by using av_freep(&audio_data[0]) * + * @see enum AVSampleFormat + * The documentation for AVSampleFormat describes the data layout. + * * @param[out] audio_data array to be filled with the pointer for each channel * @param[out] linesize aligned size for audio buffer(s), may be NULL * @param nb_channels number of audio channels