A new recommendation for listening tests? 2004-11-21 13:05:01 I would like to suggest a little change to the recommended practices in listening tests.Most of modern codecs are working based on the recent context. They usually have a way to adapt the bitrate to the content that take into consideration the past recent bitrate (a window). Many encoders also have a psychoacoustic model that take into consideration the previous psychoacoustic parameters/results.Right now, when listening to samples, we usually encode a short sample with the encoder and listen to the result.But the encoder needs some time to adapt its models (bitrate and psychoacoustic), and of course will not be able to properly adapt at the very beginning of the sample. If the sample hasn't been extracted from the full track, the encoder would have some time to adapt its models. It means that encoding a short sample is not totally representative of how this portion would be encoded in a "real" encode.That is why I am proposing the following:When encoding a short sample, allow a 1 second margin at the beginning and at the end of the sample so the encoder can adapt its models. This should not be 1s of silence, but a real 1s of content.For ease of use, this could even be taken into consideration by the testing tools.For video, the vqeg already has a similar recommendation: 1s at the beginning and 1s at the end should not be considered for tests, in order to let encoders stabilize themselves.