VideoLAN Wiki - User contributions [en]

LibVLC SampleCode SDL

2008-11-28T22:38:39Z

Erwan10:

This sample code will render a video into an SDL surface.

'''NOTE''': this requires the "vmem" video output which was checked in on March 21st, 2008. Update Nov 28th, 2008 to work with vlc-1.0.0(git).

<pre>
/* libSDL and libVLC sample code
* Copyright © 2008 Sam Hocevar <sam@zoy.org>
* license: [http://en.wikipedia.org/wiki/WTFPL WTFPL] */

#include <stdio.h>
#include <stdint.h>
#include <math.h>
#include <stdlib.h>

#include <SDL.h>
#include <SDL_mutex.h>

#include <vlc/vlc.h>

#define WIDTH 640
#define HEIGHT 480

#define VIDEOWIDTH 320
#define VIDEOHEIGHT 240

struct ctx
{
SDL_Surface *surf;
SDL_mutex *mutex;
};

static void catch (libvlc_exception_t *ex)
{
if(libvlc_exception_raised(ex))
{
fprintf(stderr, "exception: %s\n", libvlc_exception_get_message(ex));
exit(1);
}

libvlc_exception_clear(ex);
}

#ifdef VLC09X
static void * lock(struct ctx *ctx)
{
SDL_LockMutex(ctx->mutex);
SDL_LockSurface(ctx->surf);
return ctx->surf->pixels;
}
#else
static void lock(struct ctx *ctx, void **pp_ret)
{
SDL_LockMutex(ctx->mutex);
SDL_LockSurface(ctx->surf);
*pp_ret = ctx->surf->pixels;
}
#endif

static void unlock(struct ctx *ctx)
{
/* VLC just rendered the video, but we can also render stuff */
uint16_t *pixels = (uint16_t *)ctx->surf->pixels;
int x, y;

for(y = 10; y < 40; y++)
for(x = 10; x < 40; x++)
if(x < 13 || y < 13 || x > 36 || y > 36)
pixels[y * VIDEOWIDTH + x] = 0xffff;
else
pixels[y * VIDEOWIDTH + x] = 0x0;

SDL_UnlockSurface(ctx->surf);
SDL_UnlockMutex(ctx->mutex);
}

int main(int argc, char *argv[])
{
char clock[64], cunlock[64], cdata[64];
char width[32], height[32], pitch[32];
libvlc_exception_t ex;
libvlc_instance_t *libvlc;
libvlc_media_t *m;
libvlc_media_player_t *mp;
char const *vlc_argv[] =
{
"-q",
//"-vvvvv",
"--plugin-path", VLC_TREE "/modules",
"--ignore-config", /* Don't use VLC's config files */
"--noaudio",
"--vout", "vmem",
"--vmem-width", width,
"--vmem-height", height,
"--vmem-pitch", pitch,
"--vmem-chroma", "RV16",
"--vmem-lock", clock,
"--vmem-unlock", cunlock,
"--vmem-data", cdata,
};
int vlc_argc = sizeof(vlc_argv) / sizeof(*vlc_argv);

SDL_Surface *screen, *empty;
SDL_Event event;
SDL_Rect rect;
int done = 0, action = 0, pause = 0, n = 0;

struct ctx ctx;

/*
* Initialise libSDL
*/
if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_EVENTTHREAD) == -1)
{
printf("cannot initialize SDL\n");
return EXIT_FAILURE;
}

empty = SDL_CreateRGBSurface(SDL_SWSURFACE, VIDEOWIDTH, VIDEOHEIGHT,
32, 0, 0, 0, 0);
ctx.surf = SDL_CreateRGBSurface(SDL_SWSURFACE, VIDEOWIDTH, VIDEOHEIGHT,
16, 0x001f, 0x07e0, 0xf800, 0);

ctx.mutex = SDL_CreateMutex();

int options = SDL_ANYFORMAT | SDL_HWSURFACE | SDL_DOUBLEBUF;

screen = SDL_SetVideoMode(WIDTH, HEIGHT, 0, options);
if(!screen)
{
printf("cannot set video mode\n");
return EXIT_FAILURE;
}

/*
* Initialise libVLC
*/
sprintf(clock, "%lld", (long long int)(intptr_t)lock);
sprintf(cunlock, "%lld", (long long int)(intptr_t)unlock);
sprintf(cdata, "%lld", (long long int)(intptr_t)&ctx);
sprintf(width, "%i", VIDEOWIDTH);
sprintf(height, "%i", VIDEOHEIGHT);
sprintf(pitch, "%i", VIDEOWIDTH * 2);

if(argc < 2)
{
printf("too few arguments (MRL needed)\n");
return EXIT_FAILURE;
}
libvlc_exception_init(&ex);
libvlc = libvlc_new(vlc_argc, vlc_argv, &ex);
catch(&ex);
m = libvlc_media_new(libvlc, argv[1], &ex);
catch(&ex);
mp = libvlc_media_player_new_from_media(m, &ex);
catch(&ex);
libvlc_media_release(m);

libvlc_media_player_play(mp, &ex);
catch(&ex);

/*
* Main loop
*/
rect.w = 0;
rect.h = 0;

while(!done)
{
action = 0;

/* Keys: enter (fullscreen), space (pause), escape (quit) */
while( SDL_PollEvent( &event ) )
{
switch(event.type)
{
case SDL_QUIT:
done = 1;
break;
case SDL_KEYDOWN:
action = event.key.keysym.sym;
break;
}
}

switch(action)
{
case SDLK_ESCAPE:
done = 1;
break;
case SDLK_RETURN:
options ^= SDL_FULLSCREEN;
screen = SDL_SetVideoMode(WIDTH, HEIGHT, 0, options);
break;
case ' ':
pause = !pause;
break;
}

rect.x = (int)((1. + .5 * sin(0.03 * n)) * (WIDTH - VIDEOWIDTH) / 2);
rect.y = (int)((1. + .5 * cos(0.03 * n)) * (HEIGHT - VIDEOHEIGHT) / 2);

if(!pause)
n++;

/* Blitting the surface does not prevent it from being locked and
* written to by another thread, so we use this additional mutex. */
SDL_LockMutex(ctx.mutex);
SDL_BlitSurface(ctx.surf, NULL, screen, &rect);
SDL_UnlockMutex(ctx.mutex);

SDL_Flip(screen);
SDL_Delay(10);

SDL_BlitSurface(empty, NULL, screen, &rect);
}

/*
* Stop stream and clean up libVLC
*/
libvlc_media_player_stop(mp, &ex);
catch(&ex);

libvlc_media_player_release(mp);
libvlc_release(libvlc);

/*
* Close window and clean up libSDL
*/
SDL_DestroyMutex(ctx.mutex);
SDL_FreeSurface(ctx.surf);
SDL_FreeSurface(empty);

SDL_Quit();

return 0;
}
</pre>

LibVLC SampleCode SDL

2008-11-28T22:36:02Z

Erwan10:

This sample code will render a video into an SDL surface.

'''NOTE''': this requires the "vmem" video output which was checked in on March 21st, 2008.
Update Nov 28th, 2008 to work with vlc-1.0.0(git)

<pre>
/* libSDL and libVLC sample code
* Copyright © 2008 Sam Hocevar <sam@zoy.org>
* license: [http://en.wikipedia.org/wiki/WTFPL WTFPL] */

#include <stdio.h>
#include <stdint.h>
#include <math.h>
#include <stdlib.h>

#include <SDL.h>
#include <SDL_mutex.h>

#include <vlc/vlc.h>

#define WIDTH 640
#define HEIGHT 480

#define VIDEOWIDTH 320
#define VIDEOHEIGHT 240

struct ctx
{
SDL_Surface *surf;
SDL_mutex *mutex;
};

static void catch (libvlc_exception_t *ex)
{
if(libvlc_exception_raised(ex))
{
fprintf(stderr, "exception: %s\n", libvlc_exception_get_message(ex));
exit(1);
}

libvlc_exception_clear(ex);
}

#ifdef VLC09X
static void * lock(struct ctx *ctx)
{
SDL_LockMutex(ctx->mutex);
SDL_LockSurface(ctx->surf);
return ctx->surf->pixels;
}
#else
static void lock(struct ctx *ctx, void **pp_ret)
{
SDL_LockMutex(ctx->mutex);
SDL_LockSurface(ctx->surf);
*pp_ret = ctx->surf->pixels;
}
#endif

static void unlock(struct ctx *ctx)
{
/* VLC just rendered the video, but we can also render stuff */
uint16_t *pixels = (uint16_t *)ctx->surf->pixels;
int x, y;

for(y = 10; y < 40; y++)
for(x = 10; x < 40; x++)
if(x < 13 || y < 13 || x > 36 || y > 36)
pixels[y * VIDEOWIDTH + x] = 0xffff;
else
pixels[y * VIDEOWIDTH + x] = 0x0;

SDL_UnlockSurface(ctx->surf);
SDL_UnlockMutex(ctx->mutex);
}

int main(int argc, char *argv[])
{
char clock[64], cunlock[64], cdata[64];
char width[32], height[32], pitch[32];
libvlc_exception_t ex;
libvlc_instance_t *libvlc;
libvlc_media_t *m;
libvlc_media_player_t *mp;
char const *vlc_argv[] =
{
"-q",
//"-vvvvv",
"--plugin-path", VLC_TREE "/modules",
"--ignore-config", /* Don't use VLC's config files */
"--noaudio",
"--vout", "vmem",
"--vmem-width", width,
"--vmem-height", height,
"--vmem-pitch", pitch,
"--vmem-chroma", "RV16",
"--vmem-lock", clock,
"--vmem-unlock", cunlock,
"--vmem-data", cdata,
};
int vlc_argc = sizeof(vlc_argv) / sizeof(*vlc_argv);

SDL_Surface *screen, *empty;
SDL_Event event;
SDL_Rect rect;
int done = 0, action = 0, pause = 0, n = 0;

struct ctx ctx;

/*
* Initialise libSDL
*/
if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_EVENTTHREAD) == -1)
{
printf("cannot initialize SDL\n");
return EXIT_FAILURE;
}

empty = SDL_CreateRGBSurface(SDL_SWSURFACE, VIDEOWIDTH, VIDEOHEIGHT,
32, 0, 0, 0, 0);
ctx.surf = SDL_CreateRGBSurface(SDL_SWSURFACE, VIDEOWIDTH, VIDEOHEIGHT,
16, 0x001f, 0x07e0, 0xf800, 0);

ctx.mutex = SDL_CreateMutex();

int options = SDL_ANYFORMAT | SDL_HWSURFACE | SDL_DOUBLEBUF;

screen = SDL_SetVideoMode(WIDTH, HEIGHT, 0, options);
if(!screen)
{
printf("cannot set video mode\n");
return EXIT_FAILURE;
}

/*
* Initialise libVLC
*/
sprintf(clock, "%lld", (long long int)(intptr_t)lock);
sprintf(cunlock, "%lld", (long long int)(intptr_t)unlock);
sprintf(cdata, "%lld", (long long int)(intptr_t)&ctx);
sprintf(width, "%i", VIDEOWIDTH);
sprintf(height, "%i", VIDEOHEIGHT);
sprintf(pitch, "%i", VIDEOWIDTH * 2);

if(argc < 2)
{
printf("too few arguments (MRL needed)\n");
return EXIT_FAILURE;
}
libvlc_exception_init(&ex);
libvlc = libvlc_new(vlc_argc, vlc_argv, &ex);
catch(&ex);
m = libvlc_media_new(libvlc, argv[1], &ex);
catch(&ex);
mp = libvlc_media_player_new_from_media(m, &ex);
catch(&ex);
libvlc_media_release(m);

libvlc_media_player_play(mp, &ex);
catch(&ex);

/*
* Main loop
*/
rect.w = 0;
rect.h = 0;

while(!done)
{
action = 0;

/* Keys: enter (fullscreen), space (pause), escape (quit) */
while( SDL_PollEvent( &event ) )
{
switch(event.type)
{
case SDL_QUIT:
done = 1;
break;
case SDL_KEYDOWN:
action = event.key.keysym.sym;
break;
}
}

switch(action)
{
case SDLK_ESCAPE:
done = 1;
break;
case SDLK_RETURN:
options ^= SDL_FULLSCREEN;
screen = SDL_SetVideoMode(WIDTH, HEIGHT, 0, options);
break;
case ' ':
pause = !pause;
break;
}

rect.x = (int)((1. + .5 * sin(0.03 * n)) * (WIDTH - VIDEOWIDTH) / 2);
rect.y = (int)((1. + .5 * cos(0.03 * n)) * (HEIGHT - VIDEOHEIGHT) / 2);

if(!pause)
n++;

/* Blitting the surface does not prevent it from being locked and
* written to by another thread, so we use this additional mutex. */
SDL_LockMutex(ctx.mutex);
SDL_BlitSurface(ctx.surf, NULL, screen, &rect);
SDL_UnlockMutex(ctx.mutex);

SDL_Flip(screen);
SDL_Delay(10);

SDL_BlitSurface(empty, NULL, screen, &rect);
}

/*
* Stop stream and clean up libVLC
*/
libvlc_media_player_stop(mp, &ex);
catch(&ex);

libvlc_media_player_release(mp);
libvlc_release(libvlc);

/*
* Close window and clean up libSDL
*/
SDL_DestroyMutex(ctx.mutex);
SDL_FreeSurface(ctx.surf);
SDL_FreeSurface(empty);

SDL_Quit();

return 0;
}
</pre>