J2ME Streaming Media Technology realization discussion [2]

Cleverpig said "Some formats of media files do not support segmented playback because they do not contain index information in their files."

Just as you can't seek when you read a file in a sequential way ...

This problem can be solved by manually (or by using a program) to split the files and deploy them to the server.

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And "with the release of the iTunes4.9 version, podcaster (pod podcasts) can build their own podcast and make it more appealing by adding slide-style pictures." And the URL in the additional information can also allow the user door to find other podcast resources freely. This became the "great Earthquake" of the podcast World. At present this feature is transplanted to mobile phone by dividing "chapter" to complete, the podcast resource file is divided into several chapters, so that do not have "replay/positioning" ability of mobile phone to play.

But another challenge will be in front of mobile users, for example: Mobile listening must manage interrupt events. When we are starting to play the 20-40-minute podcast, a phone call or text message suddenly arrives, which will cause the playback to be interrupted. At this point we can only choose to reopen podcast to hear from the beginning or not in the mood to hear from the beginning. In addition, the media file format problem is also a "nightmare" for mobile users, most mobile phones do not support MP3 or AAC this podcast file format, but they all support the 3GP standard AMR format file. And can save a few trillion MP3 or AAC files of the mobile phone is not very popular.

But tea Vui Huang made Javacast changed all this. The software is to convert MP3 music to a mobile phone that can play. 3GP standard AMR (audio recording format) format. You can go to http://www.ringtone4me.com/to see, there are some links with such functional software.

Javacast's author,--tea Vui Huang, also a mobcast author, has produced a set of processing tools to convert podcast to a Java MIDlet (the user only needs to invoke Javacast wireless download this J2ME application on the phone. and can play podcast). This makes it easy for those podcasters to get their podcast by simply adding a link to download the MIDlet.

Huang's mobcast, indeed very famous, a few months ago, when I wrote Toodoupodcastmidlet saw a lot of people introduced him, but is not even http://www.geocities.com/tvhuangsg/mobcast /This address, so has not been to see ticket.

Convert various formats of video to 3GP, convert various formats of audio for AMR, these in the open source software MPlayer Hand is picked, just to understand the mplayer parameters can do. So thanks to MPlayer, I am also able to make mobile phone watching traffic live video, thank those MPlayer developers!

"Mobile listening must be managed for interrupt events," and this really needs to be considered. When entering the paused state, you need to inform the playback thread to pause, while the connection thread will not crawl the server's media data at the same time; when the interface switches back, the playback thread continues to replay and the thread continues downloading the music.

The owner said "can be manually (or using the program) to partition the file after deployment to the server to solve," I think, simple file segmentation is not enough, or just for WAV this raw data format. The music file should be mencoder decomposed into a section of the music file on the server, MEncoder will handle each section of the format of the problem to ensure the independent playback, so that the mobile phone download only to follow the number of a paragraph to download, the server no longer need to calculate and add header information.

In the ointment, if two players switch to play, there will be a card in the middle of the sound.

Cleverpig said "If you are interested, you can see Jffmpeg, a Java media framework capable of handling audio and video.

"and" thought for a moment, proposed a "mobile audio streaming gateway" idea: You can use the server "real-time" conversion format, MP3, WAV, such as format audio into AMR format, of course, can also do segmentation, regardless of the audio source is what (even podcast) can be downloaded to the phone to listen to. But in doing so, the load on the server is a problem, although the collected audio source is not processed again.

In fact, I originally wrote Toodoupodcast is such a concept, because those podcasts provide the music format does not match the mobile phone playback, so I use toodoupodcast such a Java Web Service invoke FFmpeg tool for audio conversion. Conversion format, is really a very CPU resources, and the time is very long, if the user more, the server pressure is great.

So now do the segmentation is also good, so that more suitable for mobile phone users.

Jffmpeg should be a Java encapsulation of the tools written by FFmpeg this c.

The other package is

http://fobs.sourceforge.net/

FOBS, the C + + & JMF wrapper for FFmpeg.