/*
 * mvrgb -- extract image from movie into rgb file
 *
 * mvrgb file.mv [track] frame
 */
#include <bstring.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <dmedia/dm_params.h>
#include <dmedia/moviefile.h>

#define MVPR(s) fprintf(stderr, "%s: %s\n", s, mvGetErrorStr(mvGetErrno()))
#define EMV(func, s) if (func == DM_FAILURE) { MVPR(s); exit(1); }

#include <gl/image.h>

void
dump_frame(char * data, int xsize, int ysize, char *fname)
{
    IMAGE *image;
    unsigned short rbuf[1024];
    unsigned short gbuf[1024];
    unsigned short bbuf[1024];
    int x, y;

    image = iopen(fname, "w", RLE(1), 3, xsize, ysize, 3);

    for( y = 0 ; y < ysize ; y++ ) {
        for( x = 0 ; x < xsize ; x++ ) {
            data++;
            bbuf[x] = *data++;
            gbuf[x] = *data++;
            rbuf[x] = *data++;
        }
        (void)putrow(image, rbuf, ysize - y - 1, 0);
        (void)putrow(image, gbuf, ysize - y - 1, 1);
        (void)putrow(image, bbuf, ysize - y - 1, 2);
    }
    (void)iclose(image);
}

main(int argc, char **argv)
{
	double rate;
	MVid movie, track;
	MVtime dur;
	MVtimescale tscale; 
	MVframe nframes;
	int frameno;
	size_t nbytes;
        MVtime mvtime;
	DMparams *p;
	int wid, ht;
	char *buf;

	char *mvname = argv[1];
	int trackno;
	char fname[16];

	if (argc != 3 && argc != 4) {
		fprintf(stderr, "usage: %s file.mv [trackno] frameno\n",
				argv[0]);
		exit(1);
	}
	trackno = argc == 4 ? atoi(argv[2]) : 0;
	frameno = atoi(argv[argc - 1]);

	EMV(mvOpenFile(mvname, O_RDONLY, &movie), mvname);

	tscale = mvGetMovieTimeScale(movie);
	EMV(mvFindTrackByIndex(movie, trackno, &track), "find track N");
	nframes = mvGetTrackLength(track);
	if (frameno >= nframes) {
		fprintf(stderr, "%s: %s has %d frames\n",
			argv[0], mvname, nframes);
		exit(1);
	}
	dmParamsCreate(&p);
	EMV(mvGetTrackDataParams(track, 0, p), "get track data params");
	dmParamsSetEnum(p, DM_IMAGE_PACKING, DM_IMAGE_PACKING_XBGR);
	dmParamsSetEnum(p, DM_IMAGE_INTERLACING, DM_IMAGE_NONINTERLACED);
	nbytes = dmImageFrameSize(p);
	if ((buf = malloc(nbytes)) == NULL) {
		fprintf(stderr, "%d: malloc failed\n", argv[0]);
		exit(1);
	}
	
	rate = mvGetImageRate(track);
	dur = (long long)((double)tscale/rate);
        mvtime = (long long)frameno * dur;
	EMV(mvRenderMovieToImageBuffer(movie, mvtime, tscale, buf, p),
							"render to buffer");
	wid = mvGetImageWidth(track);
	ht = mvGetImageHeight(track);
	sprintf(fname, "%05d.rgb", frameno);
	dump_frame(buf, wid, ht, fname);
	exit(0);
}