*
* Note that this library only handles codecs (mpeg, mpeg4, etc...),
* not file formats (avi, vob, etc...). See library 'libavformat' for the
- * format handling
+ * format handling
*/
#include <stdlib.h>
#define INBUF_SIZE 4096
/*
- * Audio encoding example
+ * Audio encoding example
*/
void audio_encode_example(const char *filename)
{
}
c= avcodec_alloc_context();
-
+
/* put sample parameters */
c->bit_rate = 64000;
c->sample_rate = 44100;
fprintf(stderr, "could not open codec\n");
exit(1);
}
-
+
/* the codec gives us the frame size, in samples */
frame_size = c->frame_size;
samples = malloc(frame_size * 2 * c->channels);
fprintf(stderr, "could not open %s\n", filename);
exit(1);
}
-
+
/* encode a single tone sound */
t = 0;
tincr = 2 * M_PI * 440.0 / c->sample_rate;
}
/*
- * Audio decoding.
+ * Audio decoding.
*/
void audio_decode_example(const char *outfilename, const char *filename)
{
uint8_t inbuf[INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE], *inbuf_ptr;
printf("Audio decoding\n");
-
+
/* set end of buffer to 0 (this ensures that no overreading happens for damaged mpeg streams) */
memset(inbuf + INBUF_SIZE, 0, FF_INPUT_BUFFER_PADDING_SIZE);
fprintf(stderr, "could not open codec\n");
exit(1);
}
-
+
outbuf = malloc(AVCODEC_MAX_AUDIO_FRAME_SIZE);
f = fopen(filename, "rb");
av_free(c);
exit(1);
}
-
+
/* decode until eof */
inbuf_ptr = inbuf;
for(;;) {
inbuf_ptr = inbuf;
while (size > 0) {
- len = avcodec_decode_audio(c, (short *)outbuf, &out_size,
+ len = avcodec_decode_audio(c, (short *)outbuf, &out_size,
inbuf_ptr, size);
if (len < 0) {
fprintf(stderr, "Error while decoding\n");
}
/*
- * Video encoding example
+ * Video encoding example
*/
void video_encode_example(const char *filename)
{
c= avcodec_alloc_context();
picture= avcodec_alloc_frame();
-
+
/* put sample parameters */
c->bit_rate = 400000;
/* resolution must be a multiple of two */
- c->width = 352;
+ c->width = 352;
c->height = 288;
/* frames per second */
- c->frame_rate = 25;
- c->frame_rate_base= 1;
+ c->time_base= (AVRational){1,25};
c->gop_size = 10; /* emit one intra frame every ten frames */
c->max_b_frames=1;
+ c->pix_fmt = PIX_FMT_YUV420P;
/* open it */
if (avcodec_open(c, codec) < 0) {
fprintf(stderr, "could not open codec\n");
exit(1);
}
-
+
/* the codec gives us the frame size, in samples */
f = fopen(filename, "wb");
fprintf(stderr, "could not open %s\n", filename);
exit(1);
}
-
+
/* alloc image and output buffer */
outbuf_size = 100000;
outbuf = malloc(outbuf_size);
size = c->width * c->height;
picture_buf = malloc((size * 3) / 2); /* size for YUV 420 */
-
+
picture->data[0] = picture_buf;
picture->data[1] = picture->data[0] + size;
picture->data[2] = picture->data[1] + size / 4;
/* get the delayed frames */
for(; out_size; i++) {
fflush(stdout);
-
+
out_size = avcodec_encode_video(c, outbuf, outbuf_size, NULL);
printf("write frame %3d (size=%5d)\n", i, out_size);
fwrite(outbuf, 1, out_size, f);
}
/*
- * Video decoding example
+ * Video decoding example
*/
-void pgm_save(unsigned char *buf,int wrap, int xsize,int ysize,char *filename)
+void pgm_save(unsigned char *buf,int wrap, int xsize,int ysize,char *filename)
{
FILE *f;
int i;
fprintf(stderr, "could not open codec\n");
exit(1);
}
-
+
/* the codec gives us the frame size, in samples */
f = fopen(filename, "rb");
fprintf(stderr, "could not open %s\n", filename);
exit(1);
}
-
+
frame = 0;
for(;;) {
size = fread(inbuf, 1, INBUF_SIZE, f);
/* NOTE1: some codecs are stream based (mpegvideo, mpegaudio)
and this is the only method to use them because you cannot
- know the compressed data size before analysing it.
+ know the compressed data size before analysing it.
BUT some other codecs (msmpeg4, mpeg4) are inherently frame
based, so you must call them with all the data for one
feed decoder and see if it could decode a frame */
inbuf_ptr = inbuf;
while (size > 0) {
- len = avcodec_decode_video(c, picture, &got_picture,
+ len = avcodec_decode_video(c, picture, &got_picture,
inbuf_ptr, size);
if (len < 0) {
fprintf(stderr, "Error while decoding frame %d\n", frame);
/* the picture is allocated by the decoder. no need to
free it */
snprintf(buf, sizeof(buf), outfilename, frame);
- pgm_save(picture->data[0], picture->linesize[0],
+ pgm_save(picture->data[0], picture->linesize[0],
c->width, c->height, buf);
frame++;
}
/* some codecs, such as MPEG, transmit the I and P frame with a
latency of one frame. You must do the following to have a
chance to get the last frame of the video */
- len = avcodec_decode_video(c, picture, &got_picture,
+ len = avcodec_decode_video(c, picture, &got_picture,
NULL, 0);
if (got_picture) {
printf("saving last frame %3d\n", frame);
fflush(stdout);
-
+
/* the picture is allocated by the decoder. no need to
free it */
snprintf(buf, sizeof(buf), outfilename, frame);
- pgm_save(picture->data[0], picture->linesize[0],
+ pgm_save(picture->data[0], picture->linesize[0],
c->width, c->height, buf);
frame++;
}
-
+
fclose(f);
avcodec_close(c);
printf("\n");
}
-// simple example how the options could be used
-int options_example(int argc, char* argv[])
-{
- AVCodec* codec = avcodec_find_encoder_by_name((argc > 1) ? argv[2] : "mpeg4");
- const AVOption* c;
- AVCodecContext* avctx;
-#define DEF_SIZE 5000
- char* def = av_malloc(DEF_SIZE);
- const char* col = "";
- int i = 0;
-
- if (!codec)
- return -1;
- c = codec->options;
- avctx = avcodec_alloc_context();
- *def = 0;
-
- if (c) {
- const AVOption *stack[FF_OPT_MAX_DEPTH];
- int depth = 0;
- for (;;) {
- if (!c->name) {
- if (c->help) {
- stack[depth++] = c;
- c = (const AVOption*)c->help;
- } else {
- if (depth == 0)
- break; // finished
- c = stack[--depth];
- c++;
- }
- } else {
- int t = c->type & FF_OPT_TYPE_MASK;
- printf("Config %s %s\n",
- t == FF_OPT_TYPE_BOOL ? "bool " :
- t == FF_OPT_TYPE_DOUBLE ? "double " :
- t == FF_OPT_TYPE_INT ? "integer" :
- t == FF_OPT_TYPE_STRING ? "string " :
- "unknown??", c->name);
- switch (t) {
- case FF_OPT_TYPE_BOOL:
- i += snprintf(def + i, DEF_SIZE-i, "%s%s=%s",
- col, c->name,
- c->defval != 0. ? "on" : "off");
- break;
- case FF_OPT_TYPE_DOUBLE:
- i += snprintf(def + i, DEF_SIZE-i, "%s%s=%f",
- col, c->name, c->defval);
- break;
- case FF_OPT_TYPE_INT:
- i += snprintf(def + i, DEF_SIZE-i, "%s%s=%d",
- col, c->name, (int) c->defval);
- break;
- case FF_OPT_TYPE_STRING:
- if (c->defstr) {
- char* d = av_strdup(c->defstr);
- char* f = strchr(d, ',');
- if (f)
- *f = 0;
- i += snprintf(def + i, DEF_SIZE-i, "%s%s=%s",
- col, c->name, d);
- av_free(d);
- }
- break;
- }
- col = ":";
- c++;
- }
- }
- }
- printf("Default Options: %s\n", def);
- av_free(def);
- return 0;
-}
-
-
int main(int argc, char **argv)
{
const char *filename;
you wish to have smaller code */
avcodec_register_all();
-#ifdef OPT_TEST
- options_example(argc, argv);
-#else
if (argc <= 1) {
audio_encode_example("/tmp/test.mp2");
audio_decode_example("/tmp/test.sw", "/tmp/test.mp2");
// audio_decode_example("/tmp/test.sw", filename);
video_decode_example("/tmp/test%d.pgm", filename);
-#endif
return 0;
}
projects / ffmpeg / blobdiff