+/*
+ * copyright (c) 2001 Fabrice Bellard
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
/**
* @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 'libavformat' for the
- * format handling
+ * format handling
*/
#include <stdlib.h>
#include <string.h>
#include <math.h>
+#define PI 3.14159265358979323846
+
#ifdef HAVE_AV_CONFIG_H
#undef HAVE_AV_CONFIG_H
#endif
#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;
+ tincr = 2 * PI * 440.0 / c->sample_rate;
for(i=0;i<200;i++) {
for(j=0;j<frame_size;j++) {
samples[2*j] = (int)(sin(t) * 10000);
}
/*
- * 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);
/* find the mpeg audio decoder */
codec = avcodec_find_decoder(CODEC_ID_MP2);
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->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");
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;
/* 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;
picture= avcodec_alloc_frame();
if(codec->capabilities&CODEC_CAP_TRUNCATED)
- c->flags|= CODEC_FLAG_TRUNCATED; /* we dont send complete frames */
+ c->flags|= CODEC_FLAG_TRUNCATED; /* we do not send complete frames */
- /* for some codecs, such as msmpeg4 and mpeg4, width and height
- MUST be initialized there because these info are not available
- in the bitstream */
+ /* For some codecs, such as msmpeg4 and mpeg4, width and height
+ MUST be initialized there because this information is not
+ available in the bitstream. */
/* 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, "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);
/* must be called before using avcodec lib */
avcodec_init();
- /* register all the codecs (you can also register only the codec
- you wish to have smaller code */
+ /* register all the codecs */
avcodec_register_all();
if (argc <= 1) {
projects / ffmpeg / blobdiff