000_FLVEncoder.
000_FLVEncoder.
000_FLVEncoder.book Page 3 Friday, August 12, 2005 3:50 PM Contents Using Flash Video Encoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 About Flash Video and Flash Video Encoder . . . . . . . . . . . . . . . . . . . . . . 6 About Flash Video Exporter (QuickTime Export plug-in) . . . . . . . . . . . . 6 Supported video compression codecs for Flash Video . . . . . . . . . . . . . . 7 Comparing the On2 VP6 and Sorenson Spark video codecs . . . . . .
000_FLVEncoder.
000_FLVEncoder.book Page 5 Friday, August 12, 2005 3:50 PM Using Flash Video Encoder Macromedia Flash 8 Video Encoder is a stand-alone video encoding application that lets you encode video in Macromedia Flash Video (FLV) format. The FLV format lets you easily incorporate video into a web page or Flash document in a format that almost anyone can view using the Flash Player.
000_FLVEncoder.book Page 6 Friday, August 12, 2005 3:50 PM About Flash Video and Flash Video Encoder Flash Video offers technological and creative benefits that let you create rich, immersive experiences that combine video presentations with data, graphics, sound, and interactive control. Flash Video provides full creative control and integrates easily into your website.
000_FLVEncoder.book Page 7 Friday, August 12, 2005 3:50 PM The following video-editing applications are supported by the QuickTime Export plug-in: ■ Adobe After Effects (Windows and Macintosh) ■ Apple FinalCut Pro (Macintosh) ■ Apple QuickTime Pro (Windows and Macintosh) ■ Avid Xpress DV (Windows and Macintosh) N OT E Avid Xpress DV does not support the encoding of an alpha channel when you use it to export to the FLV video format.
000_FLVEncoder.book Page 8 Friday, August 12, 2005 3:50 PM It’s important to note that interframe codecs also use intraframes. Intraframes are used as the reference frames (keyframes) for the interframes. Both the On2 VP6 and Sorenson Spark codecs always begin with a keyframe. Each keyframe becomes the main reference frame for the following interframes. Whenever the next frame is significantly different from the previous frame, the codec compresses a new keyframe.
000_FLVEncoder.book Page 9 Friday, August 12, 2005 3:50 PM Frame rates Video is a sequence of images that appear on the screen in rapid succession, giving the illusion of motion. The number of frames that appear every second is known as the frame rate, and it is measured in frames per second (fps). The higher the frame rate, the more frames per second are used to display the sequence of images, resulting in smoother motion.
000_FLVEncoder.book Page 10 Friday, August 12, 2005 3:50 PM Data rates The data rate affects the quality of a video clip and the audience that can download the file given their bandwidth constraints. When you deliver video using the Internet, you should produce files using lower data rates. Users with fast Internet connections can view the files with little or no delay, but dial-up users must wait for files to download.
000_FLVEncoder.book Page 11 Friday, August 12, 2005 3:50 PM An important dependency of the keyframe interval is that it affects the ability of Flash Player to seek (fast-forward or rewind) through an FLV file. Flash Player can only advance from keyframe to keyframe, so if you want to skip to different places and pause the frames, you must use a lower keyframe interval value. If you want to advance to every frame in an FLV file, use a keyframe interval value of 1.
000_FLVEncoder.book Page 12 Friday, August 12, 2005 3:50 PM About encoding video with non-square pixels Most static computer graphics use square pixels, which have a width-to-height ratio of 1:1. When working with digital video, pixels often have a different width-to height ratio and are referred to as rectangular pixels. The reason for this behavior is to allow analog video (e.g. broadcast television) and digital video (e.g. DVD video) to coexist.
000_FLVEncoder.book Page 13 Friday, August 12, 2005 3:50 PM To correct the image size when encoding using Flash Video Encoder, deselect the Maintain Aspect Ratio check box in the Advanced Encoding Settings dialog box, and enter the corrected dimensions at which to encode the video. For more information, see “Selecting advanced video encoding settings” on page 17. About encoding audio-only files The same considerations exist for audio production as for video production.
000_FLVEncoder.book Page 14 Friday, August 12, 2005 3:50 PM Encoding video with Flash Video Encoder By default, Flash Video Encoder encodes source videos using the On2 VP6 codec, which is compatible with Flash Player 8. The Flash Video Encoder uses the Sorenson Spark codec to encode video for Flash Player 7.
000_FLVEncoder.book Page 15 Friday, August 12, 2005 3:50 PM 5. Enter a filename for the encoded FLV file. If you don’t specify a filename, Flash Video Encoder uses the filename of the source video clip. When naming a file, do not enter the .flv extension; Flash Video Encoder does this automatically. You can specify a destination folder in which to save the encoded FLV file relative to the folder containing the source video clip.
000_FLVEncoder.book Page 16 Friday, August 12, 2005 3:50 PM If you exit and restart Flash Video Encoder, or if you stop and restart the queue, a dialog box appears that lets you select the file to encode. 8. The FLV encoded files are saved to the same folder as the source video files with a .flv file extension to identify them. If you encode the same file more than once, an incremental number is appended to the filename for each additional encoding.
000_FLVEncoder.book Page 17 Friday, August 12, 2005 3:50 PM To reset a skipped file for encoding: 1. Select the file or files in the encoding queue that you want to reset to the Waiting to Encode state. To select multiple files in the encoding queue, Control-click (Windows) or Command-click (Macintosh). 2. Select Edit > Reset Status. The selected file or files will be reset to the Waiting to Encode state. You can reset the status of files while Flash Video Encoder is encoding.
000_FLVEncoder.book Page 18 Friday, August 12, 2005 3:50 PM 3. Click Advanced Settings. The Advanced Flash Video Encoding Options are displayed. This dialog box lets you perform the following actions: ■ ■ ■ Specify alternate encoding settings to deliver video for different bandwidths and applications. Create cue points to trigger events. Crop and trim the video clip to alter its dimensions as well as beginning and ending frames.
000_FLVEncoder.book Page 19 Friday, August 12, 2005 3:50 PM To specify custom video encoding settings: 1. Select the file or files whose encoding settings you want to modify. To select multiple files in the encoding list, Control-click (Windows) or Command-click (Macintosh), or select File > Select All to select all files in the encoding queue. 2. Click Settings (Edit > Encoding Settings). The Flash Video Encoding Settings dialog box appears. 3. Click Advanced Settings. 4.
000_FLVEncoder.book Page 20 Friday, August 12, 2005 3:50 PM 8. Specify the quality setting for the video from the Quality pop-up menu. The quality setting determines the data rate of the encoded video. The higher the data rate, the better the quality of the encoded video clip. Select a preset Quality setting (Low, Medium, or High) to automatically select a Data Rate value. When you select Low, Medium, and High from this menu, the Maximum Data Rate text box value is updated to reflect the specified value.
000_FLVEncoder.book Page 21 Friday, August 12, 2005 3:50 PM Specifying advanced audio encoding settings The Encode Audio area of the Flash Video Encoding Settings dialog box is automatically enabled when an audio-only file is added to the encoding list (this portion of the dialog box is disabled when encoding video content with a combined audio track).
000_FLVEncoder.book Page 22 Friday, August 12, 2005 3:50 PM Each cue point consists of a name and the time at which it occurs. You specify cue point times using the format: hour:minute:second:millisecond. NO T E In addition to embedding cue points within the encoded FLV video clip, you can create cue points using the FLVPlayback component. Using this component, you can create a cue point that is not embedded in the video clip itself, and allow you greater flexibility in triggering events.
000_FLVEncoder.book Page 23 Friday, August 12, 2005 3:50 PM 6. Use the playback head to locate a specific point in the video where you want to embed a cue point. For greater precision, you can use the left and right arrow keys to move the playback head in millisecond increments. To do this, select the playback head, and then use the arrow keys to further adjust its position. To locate a specific time, use the cursor to move the playback head to the point in the video where you want to embed a cue point.
000_FLVEncoder.book Page 24 Friday, August 12, 2005 3:50 PM To learn more about the differences between event and navigation cue points, see For more information, see Chapter 22, “FLVPlayback Component (Flash Professional Only),” of the Components Language Reference. 9. Enter parameters for the selected cue point. Parameters are a set of key-value pairs that you can add to the cue point. The parameters are passed to the cue point event handler as members of the single parameter object.
000_FLVEncoder.book Page 25 Friday, August 12, 2005 3:50 PM 4. If you haven’t yet specified encoding setting for the video clip, do so now. To learn more, see “Encoding video with Flash Video Encoder” on page 14. 5. Click the Crop and Trim tab. The Crop and Trim dialog box appears. 6. Enter values for the right, left, top, and bottom edges to crop the video, or use the slider controls to visually adjust the dimensions of the video. Guides in the preview window indicate the cropped area. 7.
000_FLVEncoder.book Page 26 Friday, August 12, 2005 3:50 PM 9. When you finish cropping and trimming the video, you may select either the Cue Point or the Encoding tab to further modify the video’s encoding settings, or click OK to return to the main Flash 8 Video Encoding dialog box. If you are ready to encode your video clips, or need to add additional source video clips to encode, see “Encoding video with Flash Video Encoder” on page 14.
000_FLVEncoder.book Page 27 Friday, August 12, 2005 3:50 PM 2. Select from the respective options described in the procedures that follow. ■ ■ CAUTION ■ ■ By default, Flash Video Encoder prompts you with a warning if you attempt to stop encoding a queue, or remove a file during the encoding process. To disable the warning, deselect Warn on stop queue or remove file. By default, Flash Video Encoder increments each file you encode with the same name by appending a number to the filename.
000_FLVEncoder.book Page 28 Friday, August 12, 2005 3:50 PM The log file is stored in the following location: ■ Windows: C:\Documents and Settings\user\Application Data\Macromedia\Flash 8 Video Encoder\log.txt ■ Macintosh: Macintosh HD/Users/user/Library/Application Support/Macromedia/Flash 8 Video Encoder/log.txt To view the log file: ■ Select File > Show Log. The log file is displayed using the operating system’s default text editing application.
000_FLVEncoder.
000_FLVEncoder.
