Ticket Options
Question Details
TICKET ARCHIVE -> Dvd Player
MWC - Aug 6, 2005 - 9:46 pm
I have notice recently that when I'm playing DVDs on my mini mac the picture stops very briefly several times during playback. Why?
Matthew
Matthew
philippe99 - Aug 8, 2005 - 1:41 pm
Matthew, welcome on macosx.com
Several reasons can be the source of chopped movies:
(1) the quality of the DVD support itself; if commercial DVDs, normally there are designed to be viewed without any problem but if the written face comes dirty (or if the lens of the DVD drive comes also dirty)...
(2) the quality/severity of the compression algorithm used: some DVDs, especially the DVDs some friends/relatives built on their machines, can be highly compressed, so the player has difficulties to uncompress them and then the movie seems choppy because the uncompression task in background take a huge amount of CPU/RAM
(3) the available RAM and/or the CPU speed: if you watch a movie with Photoshop, a p2p program, iTunes and MSN, all running in background, then surely the movie will be choppy ;-)
To give you an example, on my old G3 400 MHz and 380 mB Ram, the sole iCalAlarmScheduler Apple task which runs in background was the cause of choppy playback. I was obliged to disable this task (through the Activity Monitor) to be able to watch movies flawless.
You must also know -but this is true for any application, not only DVD player- that if the program does not find any sufficient memory, it will create a 'memory space on the disk' - called the swap file-: the program will use a part of the hard disk as a memory but accessing 'this memory' is, of course, really slower than accessing a RAM board
(4) the codec used to create the movie. The codec is the algorithm used to code the film onto a -small in reality- 4.7G space. Some codecs imply an high compression ratio for video and/or audio, so that the decompression can take longer.
(5) the player used to watch the movie. I found Apple DVD player not so good in general, so I prefer to use VLC (www.videolan.org). For some codec, VLC makes the difference from Apple stuff
So, if the choppy behavior occurs repetitively up to a point you cannot watch normally the film, try to suppress background tasks/programs.
Try to make more free space on your drive
You can also think to add extra RAM.
If the choppy behavior occurs sometimes on some DVDs, except perhaps trying to use VLC instead, you'll have to live with.
I can give you another example. Now, most of the home DVD players (I say 'player', not 'recorder') have a CPU and RAM inboard comparable to a G3..only for one task..playing DVDs !!
So now imagine all the things your Mini has to do; take time to launch your Applications/Utilities/ActivityMonitor, and watch the backround tasks Mac OSX have launched at startup to help you in using your Mac (iCal, Itunes, Web connection,...), you'll easily understand that RAM amount (512 MB is a minimum, 1GB is normal, 256MB is the well known ridiculous Apple basic less than 5 months ago) and a speed hard drive (The first MacMini has a 4200 rpm hard drive, compared to the 7200 standard now) play a crucial role in a cumfortable playback of DVD
I hope that these remarks may help you. However, if you permanently face choppy DVDs playback, do not hesitate to post back a detailled description of the issue; we'll try to find a solution or at least workaround
Regards
Philippe
Several reasons can be the source of chopped movies:
(1) the quality of the DVD support itself; if commercial DVDs, normally there are designed to be viewed without any problem but if the written face comes dirty (or if the lens of the DVD drive comes also dirty)...
(2) the quality/severity of the compression algorithm used: some DVDs, especially the DVDs some friends/relatives built on their machines, can be highly compressed, so the player has difficulties to uncompress them and then the movie seems choppy because the uncompression task in background take a huge amount of CPU/RAM
(3) the available RAM and/or the CPU speed: if you watch a movie with Photoshop, a p2p program, iTunes and MSN, all running in background, then surely the movie will be choppy ;-)
To give you an example, on my old G3 400 MHz and 380 mB Ram, the sole iCalAlarmScheduler Apple task which runs in background was the cause of choppy playback. I was obliged to disable this task (through the Activity Monitor) to be able to watch movies flawless.
You must also know -but this is true for any application, not only DVD player- that if the program does not find any sufficient memory, it will create a 'memory space on the disk' - called the swap file-: the program will use a part of the hard disk as a memory but accessing 'this memory' is, of course, really slower than accessing a RAM board
(4) the codec used to create the movie. The codec is the algorithm used to code the film onto a -small in reality- 4.7G space. Some codecs imply an high compression ratio for video and/or audio, so that the decompression can take longer.
(5) the player used to watch the movie. I found Apple DVD player not so good in general, so I prefer to use VLC (www.videolan.org). For some codec, VLC makes the difference from Apple stuff
So, if the choppy behavior occurs repetitively up to a point you cannot watch normally the film, try to suppress background tasks/programs.
Try to make more free space on your drive
You can also think to add extra RAM.
If the choppy behavior occurs sometimes on some DVDs, except perhaps trying to use VLC instead, you'll have to live with.
I can give you another example. Now, most of the home DVD players (I say 'player', not 'recorder') have a CPU and RAM inboard comparable to a G3..only for one task..playing DVDs !!
So now imagine all the things your Mini has to do; take time to launch your Applications/Utilities/ActivityMonitor, and watch the backround tasks Mac OSX have launched at startup to help you in using your Mac (iCal, Itunes, Web connection,...), you'll easily understand that RAM amount (512 MB is a minimum, 1GB is normal, 256MB is the well known ridiculous Apple basic less than 5 months ago) and a speed hard drive (The first MacMini has a 4200 rpm hard drive, compared to the 7200 standard now) play a crucial role in a cumfortable playback of DVD
I hope that these remarks may help you. However, if you permanently face choppy DVDs playback, do not hesitate to post back a detailled description of the issue; we'll try to find a solution or at least workaround
Regards
Philippe
IF THIS IS YOUR QUESTION AND YOU WISH TO RESPOND, LOGIN HERE FIRST.
