I `discovered' Broadcast 2000 while searching for a Linux sound editor. What I found was much more than that.

Why write this web page? Well, like most software, the fun is in the writing and not the documenting, so the documentation that comes with Broadcast 2000 is limited, terse, quite technical and most of it is quite beyond a simpleton like me to understand. So I decided to write-down my tips and experiences and publish them on the web in the hope that you might find them useful.

It seems that Adam Williams has removed the source code of Broadcast 2000 for fear of prosecution. However, many Linux distributions ship the software and include the source code. The last release was version 2000c.

Contents

• What is Broadcast 2000?
• What is my interest in Broadcast 2000?
• Audio
  • Making a CD from an analogue cassette or Vinyl record
• Video
  • Summary
  • How big and what fps?
  • Setting the Recording Video Quality
  • Some tips on increasing performance
  • Rendering Movies
  • Handling multiple video streams in a Project
  • Positioning assests on the time-line
  • Making static titles
  • Watching Movies

But you had better go and check-out the Home Page. By the way, the web site makes a lot of amazing claims about what you can do with the software. If you are cinical, as I am, (especially if you use the Web a lot...) you would be forgiven for dismissing the site. But, having lived with the software for about 8 months I am sure it really is true, but you're going to need a beefy PC.

I have also found this handy introduction to Broadcast 2000 on one of the O'Reilly websites.

What is my interest in Broadcast 2000?

• I can record stereo at 44.1KHz with excellent results. I've used this to transcribe recordings on analogue audio cassette to CD.
• The editor is brilliant. Fast at loading, even 300MB WAV files.
• No crashes while editing.
• I've figured-out how to cut, fade-in and fade-out recordings

In more detail

Start Broadcast 2000 and start a new project with File->new and choose 2 channels of audio at 44.1KHz, no video. Click the record button on the tool bar and select a filename, plus choose WAV format to save the data. Make sure you click Monitor Audio and you should see the two VU meters displaying as you play the cassette or record. You may need to select the record-source with the sound mixer.

Cue the beginning of the cassette or LP and start recording with Broadcast 2000. When done, stop recording and click save. This will display the data as a wave-form on the main Broadcast 2000 edit window.

If you recorded several tracks at once, for example the whole of one side of an LP, you need to split up the recording and save each track in a separate WAV file. This is how;

1. find the place where the track will start. Click the Label button to mark it.
2. find the place where the track will end and label it.
3. double click between the two labels in the bar where the labels show up. This highlightes the section.
4. Choose File->Render and render the section to a new WAV file. Only the section highlighted is rendered.
5. You need to repeat this for each track. It's probably better to remove the old labels to save confusion. To remove a label, click-left on it then click Label and it is removed.

I have a medium-spec PC as follows;

• 550MHz AMD K6-2
• 128MB RAM
• 10GB disc
• BT878 Haupage TV card
• ES1371-compatible Sound
• Caldera Linux Technology Preview (2.4-pre3 kernel, released July 2000)

• I can record at 24 frames per second (fps) with an image size of 300x240 with good quality. This generates about 200MB/min of raw quicktime data. This includes a single audio track at 44.1KHz.
• I can record at 15 fps, 320x240 with fair quality, producing about 150MB/min quicktime. This includes a single audio track at 44.1KHz.
• If it try and record at 24fps with image sizes bigger than 300x240, broadcast 2000 gets behind with frame-writing too often.
• Making the image size larger than 320x240 produces unacceptably large numbers of frames with noise bars. I attribute this to a lack of disc-throughput
• About 30% of the videos I have tried recording-from give problems in that it is impossible to get a consistently high frame rate. Some of these tapes cannot be recorded with a frame rate above 5 or 6fps. It seems the TV card has difficulty scanning the video signal.
• Heroine Virtual's MPEG-2 library is vastly superior to the MPEG-1 library
• I couldn't compile MPEG-2 with Caldera 2.4, but could (with a minor correction to the Makefile for the multiplexer) with Caldera LTP
• Managed to compile Broadcast 2000 `b' release with LTP, but I think the original Broadcast 2000 release may be better for me
• I can produce good quality MPEG-2 video files at about 20MB/min which play with Xmovie

In more detail

Then you want a picture that's as big as possible. No good squinting at tiny 160x120 images. Of course if you're working on producing a video file for downloading from the Internet, then small image size might be a good idea!

A full sized PAL image is roughly 550x410. The ratio of sides of the image is 4:3 for standard low-definition TV and 16:9 for `high definition' TV.

Setting the Recording Video Quality

By choosing JPEG you can then set the JPEG compression quality. This can greatly reduce the disc storage requirements (and hence disc I/O) but increases the CPU load to process each frame.

I set compression to 65 and can reduce the disc storage from about 200MB/min down to 20MB/min (300x240x24fps). Reducing the disc I/O this way also allows me to get up to 400x300x12.5fps without any noise bars.

The next big problem is the 2.1GB maximum file limit imposed by Linux. This means that you won't be able to record for hours. In fact with RGB format you probably won't be able to record for more than a few minutes, so off-air recording is not really possible. Using JPEG and compression is the only way (I know at this time of writing) to extend Broadcast 2000's maximum recording time.

Some tips on increasing performance

• I set `frames to write to disc at once' to 75. This is found under Settings->Preferences->video. I've found the setting of this has a marked effect
• I run Broadcast 2000 as root and select `realtime priority' in Settings->Preferences->video
• Using 2.2.14 kernel (Caldera 2.4) produced inferior results, with what I describe as a "double-take" problem (repeated frame sequences) It's definitely worth upgrading to the 2.4 kernel as this completely solved the "double-take" problem a significantly increased video recording capability. For example, with the 2.2 kernel I could barely record at 256x192x24fps.
• I find that tweaking hdparm makes no difference on my machine. I get about 9.5MB/s using hdparm -t /dev/hda, but you should definitely try it yourself. The settings worth trying are -m 16 (multi-sector writes) -c 1 (32-bit transfers) and -d 1 (enable DMA). You should read the man-page before trying some of these and they can lead to corrupt filesystems.
• I turn off the video monitor during recording. I occationally quickly turn it on then off to grab a frame and see where I've got to; this usually results in getting a frame or two behind.

MPEG, on the other hand, is capable of producing very low bitrate files (under 1Mb/s) which is a better size for putting on the Internet. However, creating MPEG movies is a time-consuming process--it takes about a hour on my K6-2 system to get a 10 minute video with audio.

There are two MPEG libraries on the Broadcast 2000 Home Page, one for MPEG-2 and another (well hidden) for MPEG-1. Unless you can't compile the MPEG-2 tools, don't use the MPEG-1 tools--they're more complex to use as the video must be generated from a JPEGLIST which requires a lot of disc space and the removal of thousands of jpeg images in one directory is challenging. [``rm *'' won't work--you'll get argument list too long, so you'll have to use find with a -exec.]

The MPEG-2 tools will generate video streams of either MPEG-1 or 2 and can use stereo MPEG-1/Layer 3 audio streams.

The steps required to create a MPEG movie require the use of three separate command-line programs. I have written a simple shell script to automate this process. Here's the details of how to create a MPEG movie from Broadcast 2000;

1. Generate a quicktime file using File->Render. You don't need to include the audio stream, but it doesn't matter if you do. It seems the official MPEG standard doesn't support frame rates below 24, but Adam Williams has hacked the MPEG-2 encoder to support low frame rates of 1, 5, 10, 12 and 15. If you record at a low frame rate and want to generate a video stream at 24fps, change the frame rate with Video->Frame rate before rendering. Don't forget the output quicktime file will be larger if you increase the frame rate and there is the 2.1GB Linux single file size limit.
2. Generate a WAV file containing the audio data. It's possible that some media players will expect a sample rate of 44.1KHz. If you record at a lower sampling rate (to increase CPU performance for video recording) you can re-sample the WAV file to 44.1KHz using sox.
3. Run the encode program from the mpeg-2_movie/video directory. There are a number of parameters you need to set which control the quality (and size) of the output MPEG video stream. The trick is to make the quality acceptable and the size small.
4. Convert the WAV audio to an MPEG-3 audio stream. I use bladeenc.
5. Finally, multiplex the video and audio streams together using the mplex program from the mpeg-2_movie/mplex directory.

1. use File->Append to load a new asset
2. put a label at point where you want the new asset to start on the time-line
3. make sure there no labels between it and the start of the project
4. double-click in the label bar to select the region from the start to the label
5. make sure the only track(s) which are editable belong to the asset you want to move
6. use Edit->Paste Silence. This inserts silence into the tracks(s) pushing the video and/or audio to start at your label

1. Use the GIMP to create a PNG file with the text you require. Make sure you have a transparent background
2. Load the PNG file as a new asset with File->Append. This adds about 1s of video frames of the image at the current frame-rate
3. If you only want 1s of title, stop here. You may want to position the new asset by following these instructions.
4. If you want more than 1s of title, you must extend the asset by dragging the track end-point (the little blue right-facing triangle) with the left mouse button.
5. You may want to set fade-points on the title to get it to fade-in and out.
6. Make sure you have alpha channels enabled in Settings->Preferences->Playback otherwise the video output is just the contents of the first video track.

Disolving between video streams

Things I haven't figured out (yet)

Zooming and panning

xanim is not good at playing MPEGs. It's better for .avi and .mov files

aktion is the KDE media player but is based on xanim...

mtv is a commercial product (costs USD 10.00) which only plays MPEG-1 streams. It has a command-line player, mtvp, which can be used without having to pay anything.

xmovie is another offering from Adam Williams. Brilliant player capable of handling MPEG-1, MPEG-2 and quicktime files. Includes a random-seek widget.

Creating Movies for viewing with Windows

Quicktime movies will play with the Windows Quicktime player, which must be separately downloaded and installed.