Minim stream being throttled on QNAP NAS ?

[simoncn]

Thanks for this log and the information about how it was produced and what files were played.

The log shows that MinimServer is working correctly. It received requests from the renderer to stream 10 audio files and it responded correctly to all these requests. There were also a number of requests for artwork images. In some cases there were two requests for the same audio file: a probe request and a play request. The details of the audio file requests are shown below (scroll up and down to see all 10 audio files):

Code:

The Sun King/01_Distant Land.mp3
probe request at 12:13:04.876
play request at 12:13:06.093 (1 second later)

The Sun King/02_As The Crow Flies.mp3
probe request at 12:13:09.731

04_The Murder Wall/11_A Silent Drum.mp3
probe request at 12:15:52.570
play request at 12:15:53.702 (1 second later)

04_The Murder Wall/13_A World Beyond Man.mp3
probe request at 12:15:57.437
play request at 12:16:55.720 (58 seconds later)

04_The Murder Wall/05_Another Man's Smile.mp3
probe request at 12:16:58.291

04_The Murder Wall/11_A Silent Drum.mp3
probe request at 12:17:10.444

02_Depth of Field/01_Rosherville, Part 1.mp3
probe request at 12:17:33.605
play request at 12:17:34.837 (1 second later)

02_Depth of Field/02_Holywell Street.mp3
probe request at 12:17:40.009
play request at 12:18:04.354 (24 seconds later)

02_Depth of Field/03_Ghost Planes.mp3
probe request at 12:18:08.229

The Sun King/01_Distant Land.mp3
probe request at 12:18:57.999
play request at 12:18:59.436 (1 second later)

The probe request is reading information about the file. The play request is actually playing the file. Having both of these separated by about 1 second seems like normal behaviour.

The log doesn't show why the renderer failed to play the files despite receiving correct responses from MinimServer to all requests. A possible explanation could be that the renderer cannot cope with receiving large amounts of data in a short time. For example, the play request for the first file sends 7945700 bytes of data in 14 milliseconds, which is equivalent to 7945700 * 8 * 1000 / 14 = 45400400k bits per second. The renderer should be buffering and/or throttling this data and playing it at 128k bits per second but it might have bugs that prevent it from doing this correctly in some circumstances.

In contrast, audio data from the Radio 4 live stream arrives at a steady 320k bits per second and is played back at the same speed, so very little buffering is needed.

This problem has occurred in the past with some faulty renderers, so MinimServer provides a way to work around it by using the flowControl option of the serverOptions property. For example, if you set this option to flowControl=2x, MinimServer will slow down audio data sent to the renderer to an average rate of twice the playback rate. If you set this option to flowControl=3x, the data rate will be three times the playback rate, and so forth. It would be worth trying this to see if it helps.