LibVLC SampleCode SDL
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Rendering into a custom surface
This sample code will render a video into an SDL surface.
It requires LibVLC 1.1.1 or later. Below is a version with SDL 2.0 and one with older SDL API.
/* 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 <assert.h>
#include <SDL/SDL.h>
#include <SDL/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 *lock(void *data, void **p_pixels)
{
struct ctx *ctx = data;
SDL_LockMutex(ctx->mutex);
SDL_LockSurface(ctx->surf);
*p_pixels = ctx->surf->pixels;
return NULL; /* picture identifier, not needed here */
}
static void unlock(void *data, void *id, void *const *p_pixels)
{
struct ctx *ctx = data;
/* VLC just rendered the video, but we can also render stuff */
uint16_t *pixels = *p_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);
assert(id == NULL); /* picture identifier, not needed here */
}
static void display(void *data, void *id)
{
/* VLC wants to display the video */
(void) data;
assert(id == NULL);
}
int main(int argc, char *argv[])
{
libvlc_instance_t *libvlc;
libvlc_media_t *m;
libvlc_media_player_t *mp;
char const *vlc_argv[] =
{
"--no-audio", /* skip any audio track */
"--no-xlib", /* tell VLC to not use Xlib */
};
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;
if(argc < 2)
{
printf("Usage: %s <filename>\n", argv[0]);
return EXIT_FAILURE;
}
/*
* 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
*/
libvlc = libvlc_new(vlc_argc, vlc_argv);
m = libvlc_media_new_path(libvlc, argv[1]);
mp = libvlc_media_player_new_from_media(m);
libvlc_media_release(m);
libvlc_video_set_callbacks(mp, lock, unlock, display, &ctx);
libvlc_video_set_format(mp, "RV16", VIDEOWIDTH, VIDEOHEIGHT, VIDEOWIDTH*2);
libvlc_media_player_play(mp);
/*
* 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);
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;
}
SDL 2.0
This version works with LibVLC 1.1.1 or later and SDL 2.0.
// libSDL and libVLC sample code.
// License: [http://en.wikipedia.org/wiki/WTFPL WTFPL]
#include <stdio.h>
#include <stdint.h>
#include <math.h>
#include <stdlib.h>
#include <assert.h>
#include "SDL/SDL.h"
#include "SDL/SDL_mutex.h"
#include "vlc/vlc.h"
#define WIDTH 640
#define HEIGHT 480
#define VIDEOWIDTH 320
#define VIDEOHEIGHT 240
struct context {
SDL_Renderer *renderer;
SDL_Texture *texture;
SDL_mutex *mutex;
int n;
};
// VLC prepares to render a video frame.
static void *lock(void *data, void **p_pixels) {
struct context *c = (context *)data;
int pitch;
SDL_LockMutex(c->mutex);
SDL_LockTexture(c->texture, NULL, p_pixels, &pitch);
return NULL; // Picture identifier, not needed here.
}
// VLC just rendered a video frame.
static void unlock(void *data, void *id, void *const *p_pixels) {
struct context *c = (context *)data;
uint16_t *pixels = (uint16_t *)*p_pixels;
// We can also render stuff.
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 {
// RV16 = 5+6+5 pixels per color, BGR.
pixels[y * VIDEOWIDTH + x] = 0x02ff;
}
}
}
SDL_UnlockTexture(c->texture);
SDL_UnlockMutex(c->mutex);
}
// VLC wants to display a video frame.
static void display(void *data, void *id) {
struct context *c = (context *)data;
SDL_Rect rect;
rect.w = VIDEOWIDTH;
rect.h = VIDEOHEIGHT;
rect.x = (int)((1. + .5 * sin(0.03 * c->n)) * (WIDTH - VIDEOWIDTH) / 2);
rect.y = (int)((1. + .5 * cos(0.03 * c->n)) * (HEIGHT - VIDEOHEIGHT) / 2);
SDL_SetRenderDrawColor(c->renderer, 0, 80, 0, 255);
SDL_RenderClear(c->renderer);
SDL_RenderCopy(c->renderer, c->texture, NULL, &rect);
SDL_RenderPresent(c->renderer);
}
static void quit(int c) {
SDL_Quit();
exit(c);
}
int main(int argc, char *argv[]) {
libvlc_instance_t *libvlc;
libvlc_media_t *m;
libvlc_media_player_t *mp;
char const *vlc_argv[] = {
"--no-audio", // Don't play audio.
"--no-xlib", // Don't use Xlib.
// Apply a video filter.
//"--video-filter", "sepia",
//"--sepia-intensity=200"
};
int vlc_argc = sizeof(vlc_argv) / sizeof(*vlc_argv);
SDL_Event event;
int done = 0, action = 0, pause = 0, n = 0;
struct context context;
if(argc < 2) {
printf("Usage: %s <filename>\n", argv[0]);
return EXIT_FAILURE;
}
// Initialise libSDL.
if(SDL_Init(SDL_INIT_VIDEO) < 0) {
printf("Could not initialize SDL: %s.\n", SDL_GetError());
return EXIT_FAILURE;
}
// Create SDL graphics objects.
SDL_Window * window = SDL_CreateWindow(
"Fartplayer",
SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED,
WIDTH, HEIGHT,
SDL_WINDOW_SHOWN|SDL_WINDOW_RESIZABLE);
if (!window) {
fprintf(stderr, "Couldn't create window: %s\n", SDL_GetError());
quit(3);
}
context.renderer = SDL_CreateRenderer(window, -1, 0);
if (!context.renderer) {
fprintf(stderr, "Couldn't create renderer: %s\n", SDL_GetError());
quit(4);
}
context.texture = SDL_CreateTexture(
context.renderer,
SDL_PIXELFORMAT_BGR565, SDL_TEXTUREACCESS_STREAMING,
VIDEOWIDTH, VIDEOHEIGHT);
if (!context.texture) {
fprintf(stderr, "Couldn't create texture: %s\n", SDL_GetError());
quit(5);
}
context.mutex = SDL_CreateMutex();
// If you don't have this variable set you must have plugins directory
// with the executable or libvlc_new() will not work!
printf("VLC_PLUGIN_PATH=%s\n", getenv("VLC_PLUGIN_PATH"));
// Initialise libVLC.
libvlc = libvlc_new(vlc_argc, vlc_argv);
if(NULL == libvlc) {
printf("LibVLC initialization failure.\n");
return EXIT_FAILURE;
}
m = libvlc_media_new_path(libvlc, argv[1]);
mp = libvlc_media_player_new_from_media(m);
libvlc_media_release(m);
libvlc_video_set_callbacks(mp, lock, unlock, display, &context);
libvlc_video_set_format(mp, "RV16", VIDEOWIDTH, VIDEOHEIGHT, VIDEOWIDTH*2);
libvlc_media_player_play(mp);
// Main loop.
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:
case SDLK_q:
done = 1;
break;
case ' ':
printf("Pause toggle.\n");
pause = !pause;
break;
}
if(!pause) { context.n++; }
SDL_Delay(1000/10);
}
// Stop stream and clean up libVLC.
libvlc_media_player_stop(mp);
libvlc_media_player_release(mp);
libvlc_release(libvlc);
// Close window and clean up libSDL.
SDL_DestroyMutex(context.mutex);
SDL_DestroyRenderer(context.renderer);
quit(0);
return 0;
}
Older API
This code was used for LibVLC 0.9.x and 1.0.x.
/* 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;
}
