Method 1 works well with two stage giving an improved picture quality with modest cpu usage given that the wmv codec is less than best compared with what is available. A two stage transcode on two different boxes will be less susceptible to quality problems related to mutual or random cpu activity spikes caused by other applications. A two stage transcode may offer advantages in quality at the cost of time and hardware to effect it. Single vs Two stage transcode? A single stage transcode may work well for many situations. Or in this case 25% of the original pixel area. So scale=0.5 will half original width/height in pixels. Scale=xx determines the output size relative to source size applied to width/height ratio. The smaller the image the less compression and bandwidth needed to stream.ĭeinterlace= This command useful if you are using an interlaced source. The larger the image, the better the definition, but will require more cpu power and bandwidth. Width=xx & height=xx Determines the aspect ratio and the size of the image in pixels. ![]() So lower fps will give better quality for given bandwidth. The more fps, then the smoother the moving image, however, this uses more bandwidth and compression. As above, but relates to audio.įps=xx Frames Per Second. The more compression the lower the video quality.Īb=xx Audio Bandwidth. This parameter in effect sets the target bandwidth of the output video stream and hence the compression required. The following methods and examples deal directly with the output string found in the GUI.ĭescription of command parameters used in the methods following This should help to give an insight into how to construct a complete command line and enter the appropriate parameters. I have included an example of a complete true command line with the same parameters as the Win XP example in Method 2. The following methods and examples modify the generated stream output string. The above links will give an overview of the commands available to use to manipulate and optimise the Command output string. Documentation:Streaming_HowTo/Command_Line_Examples.Documentation:Streaming_HowTo/Advanced_Streaming_Using_the_Command_Line#Structure_of_stream_output.Web server Apache 2.2 was used in all cases.įirst a couple of reference links for further reading Hardware capability also plays an important role in this respect. See Notes and Troubleshooting for more information. There are subtle and significant differences in capability and performance of VLC versions and their respective OS platforms. Method 2:-WinXP and Ubuntu Linux (8.04 & 10.04) Method 1:-WinXP and Ubuntu Linux (8.04 & 10.04) This HowTo, the methods and examples have been tested on Operating Systems: (8.04 & 10.04) Earlier versions may work but have not been tested. This HowTo was written and tested using VLC version series 1.0.1 to 1.1.4 for Win XP.and VLC 0.9.9a to 1.0.6 for Ubuntu Linux. You will have an appreciation of the bandwidth requirements of what you are trying to achieve. Method 1 is achievable with a pair of 1Gb cpu or more machines. So you are going to need something like Intel P4 at 2.4Gb or equivalent as a minimum dedicated box to use the example method 2 in this HowTo. To start with, Video transcoding, compression and streaming is CPU intensive. The methods described below are targeting a bandwidth of around 235k. The following examples are aimed at reducing bandwidth, with a view to streaming on the internet with available upstream bandwidth being the major consideration. ![]() This HowTo is aimed at VLC users who are intending to “Live Stream” from a capture device, eg Webcam, TV camera, live audio source etc and are looking to get a little more out of the features available in VLC and wish to start to understand the command line string and explore techniques to transcode, compress and output a stream to a web site more efficiently and effectively. You may wish to read through the previous Wiki first, as it covers fundamentals which are assumed, if you have not done so already. The "Simple Stream VLC to Website" wiki employed an Out of the Box solution with no modifications to the VLC command string. 5 Description of command parameters used in the methods following.
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