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How to View
Many American Memory collections contain sound recordings, video, high-resolution images, and enhanced text that require special viewers. Most viewers can be downloaded free from vendor sites.
The links below explain the various formats used and how to access them.
Jump to:
Sound Recordings
| Sound Recording Formats | About the Format | Players | Samples |
|---|---|---|---|
| RealAudio (.ra, .ram) |
- Minimizes download time - If you have trouble using RealAudio, download the most recent version of RealPlayer |
Windows, Mac: RealPlayer | - Sample
RealAudio file - About this sample |
| MP3 (MPEG 2, Layer 3, .mp3) |
- Offers high-quality sound - Downloads faster than WAV files |
- Windows: Media Player - Mac: QuickTime Additional MP3 Players |
- Sample
MP3 - About this sample |
| WAV (WaveForm, .wav) | - Higher-quality format - Must download completely before playing - Longer download time - Windows operating systems contain WAV players - Some browsers contain media players that play WAV files |
- Windows: Media Player - Mac: QuickTime |
- Sample
WAV - About this sample |
Documents (Text and Page Images)
In general, no special viewers are required to view text in American Memory. Most images of historical documents, as well as transcriptions of documents, are displayed through your web browser.
Certain illustrations and higher-resolution images, however, require special formatting.
| Document Formats | About the Format | Viewers | Samples |
|---|---|---|---|
| TIFF (Tagged Image File Format, .tif, .tiff) |
Used for images of original pages | - Windows TIFF viewers Alternatiff InterneTIFF IrfanView Quick View Plus - Mac TIFF viewers OSX: locate "Preview" on your computer Graphic Converter |
- Sample
TIFF - About this sample |
| PCX (.pcx) |
Used for images of original illustrations | - Windows PCX viewers (pre-installed) Find "kodakimg.exe" MS Paintbrush. Find "mspaint.exe" - Windows PCX viewers Windows: IrfanView Windows: Quick View Plus Mac: Graphic Converter |
- Sample PCX - About this sample |
| PDF (Portable Document Format, .pdf) |
Used for page images | Adobe Acrobat Reader Adobe text-only download page |
- Sample PDF - About this sample |
| MrSID (Multi-resolution Seamless Image Database, .sid) |
- Used for page images - Wavelet compression technology - Decompresses only that portion of the image requested by the user |
MrSID viewer | - Sample MrSID document - About this sample |
| SGML (Standard Generalized Markup Language, .sgm) |
- Enhanced search and browse features (including linked table of contents) - Viewing illustrations within SGML files requires the TIFF/PCX tools listed above. |
No current SGML viewer is available for download. Download an older, free SGML viewer for Windows from the Oasis XML Consortium. |
- Sample SGML - About this sample |
Maps
Maps and other large images in American Memory are presented as GIF or JPEG files and require no special viewers, unless you choose to download and view maps offline.
For off-line viewing, some maps are available in the MrSID format and others are available in the JPEG2000 format.
Download and View Maps Offline
| Map Format | About the Format | Viewer | Samples |
|---|---|---|---|
| MrSID (.sid) |
- Wavelet compression technology - Decompresses only that portion of the image requested by the user - Compression ratio is approximately 22:1, depending on image content and color depth |
- MrSID viewer - IrfanView with plug-ins |
- Sample MrSID map - About this sample |
| JPEG2000 (.jp2) |
- Wavelet compression technology - Tiling supports decompression of only that portion of the image requested by the user - Compression ratio is approximately 20:1, depending on image content and color depth |
Windows: - ER Viewer 7.0 - IrfanView with plug-ins OS X:Preview supports baseline JP2 only; commercial software may be needed to view tiled JP2 files |
- Sample JPEG2000 map - About this sample |
Prints and Photographs
Most prints and photographs in American Memory are displayed in GIF and JPEG formats and require no special viewers. Some images are also offered as TIFFs—higher-resolution images with larger file sizes that require additional software.
| Print, Photograph Formats | About the Format | Viewers | Samples |
|---|---|---|---|
| TIFF (Tagged Image File Format, .tif, .tiff) |
Used for images of original prints and photographs | - Windows TIFF viewers Alternatiff InterneTIFF IrfanView Quick View Plus - Mac TIFF viewers OSX: locate "Preview" on your computer Graphic Converter |
- Sample TIFF photo - About this sample |
Video
American Memory video collections are available in the following formats:
| Motion Picture Formats | About the Format | Players | Video |
|---|---|---|---|
| MPEG (Motion Picture Experts Group, .mpg, .mpeg) |
- Highest-quality files are in the MPEG format - Average file size is about nine megabytes for each minute of motion picture |
Windows: Media Player Mac: QuickTime Additional MPEG players |
- Sample MPEG - About this sample |
| QuickTime (.mov) |
- QuickTime (Cinepak compression) - Offers smaller, downloadable files and allows films to be viewed on lower-end computers - Not as crisp as the MPEG format - Average file size is about five megabytes for each minute of motion picture - QuickTime 3 (Sorenson compression) - A streaming file format Enhanced image quality, higher resolution - Available in Dance Instruction Manuals collection - Average file size is about six megabytes for each minute of motion picture |
Windows, Mac: QuickTime Windows: Media Player |
QuickTime - Sample QuickTime - About this sample QuickTime 3 - Sample QuickTime 3 - About this sample |
| RealMedia (.rm, .ram) |
- A streaming file format - Useful for computers with slower Internet connections - Playback is slower (three to six frames per second) and may be affected by Internet traffic. |
Windows, Mac: RealPlayer | - Sample RealMedia - About this sample |
More Information about Downloading and Viewing Video
Video clips longer than four minutes may have been segmented, thereby limiting maximum file size to approximately 40 MB. A typical 28.8 Internet connection achieves a theoretical maximum download rate of approximately 3.5 KB/sec (210 K/min) under ideal conditions. Therefore, a file of 40 MB would take approximately 190 minutes (three hours, ten minutes) under optimal conditions, depending on Internet traffic.