Mercurial > repos > blastem
comparison README @ 1352:90c9922b5430
Add description of overscan settings to README
| author | Michael Pavone <pavone@retrodev.com> |
|---|---|
| date | Tue, 09 May 2017 22:57:12 -0700 |
| parents | 262c0ce8f586 |
| children | 52d9e3c36b4f |
comparison
equal
deleted
inserted
replaced
| 1351:bb0318a73b54 | 1352:90c9922b5430 |
|---|---|
| 184 "fullscreen" controls whether BlastEm starts in fullscreen or windowed mode. | 184 "fullscreen" controls whether BlastEm starts in fullscreen or windowed mode. |
| 185 This can be overridden on the command line with the -f flag. If fullscreen | 185 This can be overridden on the command line with the -f flag. If fullscreen |
| 186 is set to "off", -f will turn it on. Conversely, if fullscreen is set to "on" | 186 is set to "off", -f will turn it on. Conversely, if fullscreen is set to "on" |
| 187 in the config, -f will turn it off. | 187 in the config, -f will turn it off. |
| 188 | 188 |
| 189 The "ntsc" and "pal" sub-sections control overscan settings for the emulated | |
| 190 video output for NTSC and PAL consoles respectively. More details are available | |
| 191 in the Overscan section. | |
| 192 | |
| 193 Overscan | |
| 194 -------- | |
| 195 | |
| 196 Analog televisions generally don't display the entirety of a video frame. Some | |
| 197 portion is cropped at the edges of the display. This is called overscan. | |
| 198 Unfortunately, the amount of cropping performed varies considerably and is even | |
| 199 adjustable on many TV sets. To deal with this, BlastEm allows overscan to be | |
| 200 customized. | |
| 201 | |
| 202 Overscan values are specified in the "ntsc" and "pal" sub-sections of the | |
| 203 "video" section of the config file. The "overscan" sub-section contains four | |
| 204 settings for specifying the number of pixels cropped on each side of the | |
| 205 display: "top", "bottom", "left" and "right". | |
| 206 | |
| 207 The default settings hide the horizontal border completely for both NTSC and | |
| 208 PAL consoles. For the vertical borders, the NTSC overscan settings are chosen | |
| 209 to give square pixels with the default aspect ratio of 4:3. For PAL, the | |
| 210 default settings are set so that the PAL-exclusive V30 mode will produce a | |
| 211 visible border that is the same size as what is shown in V28 mode in NTSC. This | |
| 212 results in a slightly squished picture compared to NTSC which is probably | |
| 213 appropriate given that a PAL display has more lines than an NTSC one. | |
| 214 | |
| 189 Audio | 215 Audio |
| 190 ----- | 216 ----- |
| 191 | 217 |
| 192 The audio section contains settings that affect the audio output of BlastEm. | 218 The audio section contains settings that affect the audio output of BlastEm. |
| 193 | 219 |
| 333 probably not the native refresh rate of your monitor. Fortunately, it is | 359 probably not the native refresh rate of your monitor. Fortunately, it is |
| 334 most likely lower than your refresh rate. As long as this is true, VSync will | 360 most likely lower than your refresh rate. As long as this is true, VSync will |
| 335 generally work as long as your computer is fast enough to cope with the time | 361 generally work as long as your computer is fast enough to cope with the time |
| 336 lost waiting for VSync and the audio buffer is large enough to not run out of | 362 lost waiting for VSync and the audio buffer is large enough to not run out of |
| 337 samples during that delay. Latency will suffer a bit and you'll get a doubled | 363 samples during that delay. Latency will suffer a bit and you'll get a doubled |
| 338 frame, but things will be fine. | 364 frame every once and a while, but generally things will be fine. |
| 339 | 365 |
| 340 If you enable VSync and you're getting audio dropouts, first try doubling the | 366 If you enable VSync and you're getting audio dropouts, first try doubling the |
| 341 audio buffer setting. If you still experience dropouts, it's possible your | 367 audio buffer setting. If you still experience dropouts, it's possible your |
| 342 computer is not fast enough or that your monitor's actual refresh rate is in | 368 computer is not fast enough or that your monitor's actual refresh rate is in |
| 343 fact lower than that of the emualted console. Not much can be done about the | 369 fact lower than that of the emualted console. Not much can be done about the |