-/* avcodec API use example.
+/**
+ * @file apiexample.c
+ * avcodec API use example.
*
* Note that this library only handles codecs (mpeg, mpeg4, etc...),
- * not file formats (avi, vob, etc...). See library 'libav' for the
- * format handling
+ * not file formats (avi, vob, etc...). See library 'libavformat' for the
+ * format handling
*/
+
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define INBUF_SIZE 4096
/*
- * Audio encoding example
+ * Audio encoding example
*/
void audio_encode_example(const char *filename)
{
FILE *f;
short *samples;
float t, tincr;
- UINT8 *outbuf;
+ uint8_t *outbuf;
printf("Audio encoding\n");
}
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);
outbuf_size = 10000;
outbuf = malloc(outbuf_size);
- f = fopen(filename, "w");
+ f = fopen(filename, "wb");
if (!f) {
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;
free(samples);
avcodec_close(c);
- free(c);
+ av_free(c);
}
/*
- * Audio decoding.
+ * Audio decoding.
*/
void audio_decode_example(const char *outfilename, const char *filename)
{
AVCodecContext *c= NULL;
int out_size, size, len;
FILE *f, *outfile;
- UINT8 *outbuf;
- UINT8 inbuf[INBUF_SIZE], *inbuf_ptr;
+ uint8_t *outbuf;
+ 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);
+
/* find the mpeg audio decoder */
codec = avcodec_find_decoder(CODEC_ID_MP2);
if (!codec) {
fprintf(stderr, "could not open codec\n");
exit(1);
}
-
+
outbuf = malloc(AVCODEC_MAX_AUDIO_FRAME_SIZE);
- f = fopen(filename, "r");
+ f = fopen(filename, "rb");
if (!f) {
fprintf(stderr, "could not open %s\n", filename);
exit(1);
}
- outfile = fopen(outfilename, "w");
+ outfile = fopen(outfilename, "wb");
if (!outfile) {
- free(c);
+ 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");
free(outbuf);
avcodec_close(c);
- free(c);
+ av_free(c);
}
/*
- * Video encoding example
+ * Video encoding example
*/
void video_encode_example(const char *filename)
{
int i, out_size, size, x, y, outbuf_size;
FILE *f;
AVFrame *picture;
- UINT8 *outbuf, *picture_buf;
+ uint8_t *outbuf, *picture_buf;
printf("Video encoding\n");
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 * FRAME_RATE_BASE;
+ 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, "w");
+ f = fopen(filename, "wb");
if (!f) {
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;
/* encode 1 second of video */
for(i=0;i<25;i++) {
- printf("encoding frame %3d\r", i);
fflush(stdout);
/* prepare a dummy image */
/* Y */
/* encode the image */
out_size = avcodec_encode_video(c, outbuf, outbuf_size, picture);
+ printf("encoding frame %3d (size=%5d)\n", i, out_size);
+ fwrite(outbuf, 1, out_size, f);
+ }
+
+ /* 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);
}
free(outbuf);
avcodec_close(c);
- free(c);
- free(picture);
+ av_free(c);
+ av_free(picture);
printf("\n");
}
/*
- * 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;
int frame, size, got_picture, len;
FILE *f;
AVFrame *picture;
- UINT8 inbuf[INBUF_SIZE], *inbuf_ptr;
+ uint8_t inbuf[INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE], *inbuf_ptr;
char buf[1024];
+ /* 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);
+
printf("Video decoding\n");
/* find the mpeg1 video decoder */
fprintf(stderr, "could not open codec\n");
exit(1);
}
-
+
/* the codec gives us the frame size, in samples */
- f = fopen(filename, "r");
+ f = fopen(filename, "rb");
if (!f) {
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);
exit(1);
}
if (got_picture) {
- printf("saving frame %3d\r", frame);
+ printf("saving 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++;
}
/* 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 frame %3d\r", frame);
+ 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);
- free(c);
- free(picture);
+ av_free(c);
+ av_free(picture);
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;
- char* def = av_malloc(5000);
- 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->sub) {
- stack[depth++] = c;
- c = c->sub;
- } 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 += sprintf(def + i, "%s%s=%s",
- col, c->name,
- c->defval != 0. ? "on" : "off");
- break;
- case FF_OPT_TYPE_DOUBLE:
- i += sprintf(def + i, "%s%s=%f",
- col, c->name, c->defval);
- break;
- case FF_OPT_TYPE_INT:
- i += sprintf(def + 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 += sprintf(def + 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;
}