Frames/Samples confusion

[davidebeatrici]

Let's suppose my application receives stereo (2 channels) packets that contain a total of 960 float samples (3840 bytes in total) each:

• opus_packet_get_nb_channels() returns 2, which is correct.
• opus_packet_get_nb_frames() returns 1, which is correct because it refers to the Opus frames.
• opus_packet_get_samples_per_frame() returns 480, which is wrong because that is the number of audio frames. The Opus frame contains 960 samples.
• opus_packet_get_nb_samples() and opus_decoder_get_nb_samples() return 480, which is wrong because that is the number of audio frames. The packet contains 960 samples.

Audio/Opus frame confusion aside, the issue consists in the functions not taking the number of channels into account.

Since changing the behavior is not feasible, I would simply add a short explanation to the documentation.