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/*
Psychtoolbox3/Source/Common/SCREENGetMovieImage.c
AUTHORS:
mario.kleiner at tuebingen.mpg.de mk
PLATFORMS:
This file should build on any platform.
HISTORY:
10/23/05 mk Created.
DESCRIPTION:
Fetch an image from the specified movie object and create an OpenGL texture out of it.
Return a handle to the texture.
TO DO:
*/
#include "Screen.h"
static char useString[] = "[ texturePtr [timeindex]]=Screen('GetMovieImage', windowPtr, moviePtr, [waitForImage=1], [fortimeindex], [specialFlags = 0] [, specialFlags2 = 0]);";
static char synopsisString[] =
"Try to fetch a new texture image from movie object 'moviePtr' for visual playback/display in onscreen window 'windowPtr' and "
"return a texture-handle 'texturePtr' on successfull completion. 'waitForImage' If set to 1 (default), the function will wait "
"until the image becomes available. If set to zero, the function will just poll for a new image. If none is ready, it will return "
"a texturePtr of zero, or -1 if none will become ready because movie has reached its end and is not in loop mode. "
"On MS-Windows, polling mode is not possible, the function always waits for a new image, unless you use the GStreamer playback engine.\n"
"'fortimeindex' Don't request the next image, but the image closest to time 'fortimeindex' in seconds. The (optional) return "
"value 'timeindex' contains the exact time when the returned image should be displayed wrt. to the start of the movie - a presentation timestamp. \n"
"'specialFlags' (optional) encodes special requirements for the returned texture. A setting of 2 will request that the texture "
"is prepared for drawing it with highest possible spatial precision. See explanation of 'specialFlags' == 2 in Screen('MakeTexture') "
"for details. \n"
"'specialFlags2' (optional) More special flags: A setting of 1 tells the function to not return presentation timestamps in 'timeindex'. "
"This means that 'timeindex' will be always returned as zero and that the built-in detector for skipped frames is disabled as well. This "
"may (or may not) save a little bit of computation time during playback of very demanding movies on lower end systems, your mileage will "
"vary, depending on many factors.\n"
;
static char seeAlsoString[] = "CloseMovie PlayMovie GetMovieImage GetMovieTimeIndex SetMovieTimeIndex";
PsychError SCREENGetMovieImage(void)
{
PsychWindowRecordType *windowRecord;
PsychWindowRecordType *textureRecord;
PsychRectType rect;
double deadline, tnow;
int moviehandle = -1;
int waitForImage = TRUE;
double requestedTimeIndex = -1;
double presentation_timestamp = 0;
int rc=0;
int specialFlags = 0;
int specialFlags2 = 0;
// All sub functions should have these two lines
PsychPushHelp(useString, synopsisString, seeAlsoString);
if(PsychIsGiveHelp()) {PsychGiveHelp(); return(PsychError_none);};
PsychErrorExit(PsychCapNumInputArgs(6)); // Max. 6 input args.
PsychErrorExit(PsychRequireNumInputArgs(2)); // Min. 2 input args required.
PsychErrorExit(PsychCapNumOutputArgs(2)); // Max. 2 output args.
// Get the window record from the window record argument and get info from the window record
PsychAllocInWindowRecordArg(kPsychUseDefaultArgPosition, TRUE, &windowRecord);
// Only onscreen windows allowed:
if(!PsychIsOnscreenWindow(windowRecord)) {
PsychErrorExitMsg(PsychError_user, "GetMovieImage called on something else than an onscreen window.");
}
// Get the movie handle:
PsychCopyInIntegerArg(2, TRUE, &moviehandle);
if (moviehandle==-1) {
PsychErrorExitMsg(PsychError_user, "GetMovieImage called without valid handle to a movie object.");
}
// Get the 'waitForImage' flag: If waitForImage == true == 1, we'll do a blocking wait for
// arrival of a new image for playback. Otherwise we will return with a 0-Handle if there
// isn't any new image available.
PsychCopyInIntegerArg(3, FALSE, &waitForImage);
// Get the requested timeindex for the frame. The default is -1, which means: Get the next image,
// according to current movie playback time.
PsychCopyInDoubleArg(4, FALSE, &requestedTimeIndex);
// Get the optional specialFlags flag:
PsychCopyInIntegerArg(5, FALSE, &specialFlags);
// Get the optional specialFlags2 flag:
PsychCopyInIntegerArg(6, FALSE, &specialFlags2);
PsychGetAdjustedPrecisionTimerSeconds(&deadline);
deadline += 5;
while (rc==0) {
// With some backends (GStreamer), we can use a checkForImage of type 2 if a blocking wait is
// requested. Type 2 actually blocks inside the backend, to minimize cpu load and achieve lowest signalling delay
// once a new frame becomes available. Type 1 only polls. With the deprecated Quicktime backend, a type 1 and type 2
// check are the same - they translate into a poll for new image, and this while() loop needs to emulate a blocking
// wait via a poll-sleep cycle:
rc = PsychGetTextureFromMovie(windowRecord, moviehandle, (waitForImage != 0) ? 2 : 1, requestedTimeIndex, NULL, NULL);
PsychGetAdjustedPrecisionTimerSeconds(&tnow);
if (rc<0 || ((tnow > deadline) && (waitForImage != 0))) {
// No image available and there won't be any in the future, because the movie has reached
// its end and we are not in looped playback mode:
if (tnow > deadline) printf("PTB-ERROR: In Screen('GetMovieImage') for movie %i: Timed out while waiting for new frame after 5 seconds!\n", moviehandle);
// No new texture available: Return a negative handle:
PsychCopyOutDoubleArg(1, TRUE, -1);
// ...and an invalid timestamp:
PsychCopyOutDoubleArg(2, FALSE, -1);
// Ready!
return(PsychError_none);
}
else if (rc==0 && waitForImage == 0) {
// We should just poll once and no new texture available: Return a null-handle:
PsychCopyOutDoubleArg(1, TRUE, 0);
// ...and an invalid timestamp:
PsychCopyOutDoubleArg(2, FALSE, -1);
// Ready!
return(PsychError_none);
}
else if (rc==0 && waitForImage != 0) {
// No new texture available yet. Just sleep a bit and then retry...
// This is thankfully only needed / used for the deprecated QT backend.
PsychYieldIntervalSeconds(0.001);
}
}
// New image available: Go ahead...
// Create a texture record. Really just a window record adapted for textures.
PsychCreateWindowRecord(&textureRecord); // This also fills the window index field.
// Set mode to 'Texture':
textureRecord->windowType=kPsychTexture;
// We need to assign the screen number of the onscreen-window.
textureRecord->screenNumber=windowRecord->screenNumber;
// It is always a 32 bit texture for movie textures:
textureRecord->depth=32;
textureRecord->nrchannels = 4;
// Create default rectangle which describes the dimensions of the image. Will be overwritten
// later on.
PsychMakeRect(rect, 0, 0, 10, 10);
PsychCopyRect(textureRecord->rect, rect);
// Other setup stuff:
textureRecord->textureMemorySizeBytes= 0;
textureRecord->textureMemory=NULL;
// Assign parent window and copy its inheritable properties:
PsychAssignParentWindow(textureRecord, windowRecord);
// Try to fetch an image from the movie object and return it as texture:
PsychGetTextureFromMovie(windowRecord, moviehandle, FALSE, requestedTimeIndex, textureRecord, ((specialFlags2 & 1) ? NULL : &presentation_timestamp));
// Assign GLSL filter-/lookup-shaders if needed: usefloatformat is always == 0 as
// our current movie engine implementations only return 8 bpc fixed textures.
// The 'userRequest' flag is set if specialmode flag is set to 8.
PsychAssignHighPrecisionTextureShaders(textureRecord, windowRecord, 0, (specialFlags & 2) ? 1 : 0);
// Texture ready for consumption. Mark it valid and return handle to userspace:
PsychSetWindowRecordValid(textureRecord);
PsychCopyOutDoubleArg(1, TRUE, textureRecord->windowIndex);
// Return presentation timestamp for this image:
PsychCopyOutDoubleArg(2, FALSE, presentation_timestamp);
// Ready!
return(PsychError_none);
}
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