FLAC audio stutters at start?

[Feldon]

When I play a FLAC file, even if VLC is already open, there is a small amount of stuttering for the first couple seconds. Just wondering if there are some settings I can alter to prevent this? I'm running VLC 0.8.5 on an amd64 2800+/winXP box.

[DJ]

On occasion I get:

main warning: buffer is 97390 in advance, triggering downsampling
main warning: the mixer got a packet in the past (42902)
main warning: mixer start isn't output start (15135)
main warning: mixer start isn't output start (8)
main warning: computed PTS is out of range (181411), clearing out
main warning: timing screwed, stopping resampling
main warning: PTS is out of range (87053), dropping buffer
main warning: output PTS is out of range (203196), clearing out
main warning: PTS is out of range (-15881), dropping buffer
main warning: input PTS is out of range (184592), trashing
main warning: computed PTS is out of range (106263), clearing out
main warning: buffer is 97391 in advance, triggering downsampling
main warning: the mixer got a packet in the past (42902)
main warning: mixer start isn't output start (15135)
main warning: output date isn't PTS date, requesting resampling (-44927)
main warning: audio drift is too big (-142476), clearing out
main warning: timing screwed, stopping resampling
main warning: mixer start isn't output start (-19882)
main warning: buffer is 97367 in advance, triggering downsampling
main warning: input PTS is out of range (13771), trashing

and the file studders. But most often I get:

main warning: buffer is 97390 in advance, triggering downsampling
main warning: the mixer got a packet in the past (42902)
main warning: mixer start isn't output start (15135)
main warning: mixer start isn't output start (8)

Which seems to be the filters and converters opening and settling. Every time a file starts and ends all the libraries, DirectX and etc. are released and recalled for the next file. So the last set appears to be normal while the first set may be an encoding problem or a partially damaged file.

What this means is at the start of every file there will be a settling time that may be seen or heard as a stutter.

[kjdotts]

I believe I have a solution for your problem. Please visit this forum entry: viewtopic.php?p=86400&highlight=#86400

[DJ]

I understand that this may improve the beginning of the file but at the expense of every file that is played and yes, the file's seek time and pause time will be effected adversely. But it is also possible that this may not work for every user due to variances in converters.

I have seen many discussions regarding encoders where any encoder at the start of a file goes through a settling time and is not real accurate for the first few seconds of the encode. Accuracy of the encode always improves during a second pass. I don't believe many people consider this when making audio files and VLC's transcode options do not offer a second pass feature for anything. This may be a contributing factor to the perceived problem in this format.

Most movies for example open with a black or blank screen with no audio. If there is always leed time in sound only files then there is also no problem. Believe it or not, CDs will do the same thing if the titles are cut at the instant of sound and some converters respond to this worse than others. OOG vorbis and other sound only formats do the same thing. To me this is a user education problem.

Many kids want to tighten up there MP3 or such collection so it sounds continuous. Many would even like a feature to do segways like DJs, but to do but this the segway is made and then edited into place so the two files are now one file. If you but splice digital audio files there will always be a error or series of errors at the splice. To avoid this a segway would also be required. In a number of sound editing programs there is a way to add dead space to the beginning of a file to correct for the nut that made the file or to properly allow for delay times to be correct for a video file (again) because of the nut that didn't make it right to begin with.

Now I realize that most of us just want to be able to download and play the file without problems. But please remember there is no accounting for the nut that made the file and in most cases this is NOT a player problem.

[kjdotts]

I understand that this may improve the beginning of the file but at the expense of every file that is played and yes, the file's seek time and pause time will be effected adversely. But it is also possible that this may not work for every user due to variances in converters.

I understand what you are saying DJ, I debated the pros/cons of this "fix." In the end, the stuttering at the start of every flac file I play convinced me to live with the very small play/pause/seek delay increase. I my case, going from 300ms to 500ms is barley even noticeable...we are only talking about a 1/5 second increase.

Later!

[DJ]

I understand, and that's why there are options. But be aware that this may not work for everyone who tries to use the same setting.