求助：关于FFMPEG中avcodec_open()函数总是返回-1

[-燕赤侠-]

代码如下:

void video_encode_example(const char *filename)
{
AVCodec *codec;
AVCodecContext *c= NULL;
int i, out_size, size, x, y, outbuf_size;
FILE *f;
AVFrame *picture;
uint8_t *outbuf, *picture_buf;

printf("Video encoding\n");

/* find the mpeg1 video encoder */
codec = avcodec_find_encoder(CODEC_ID_MPEG1VIDEO);
if (!codec) {
fprintf(stderr, "codec not found\n");
exit(1);
}

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->height = 288;
/* frames per second */
c->time_base.den = 1;
c->time_base.num = 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)/*这个函数总是返回-1*/ {
fprintf(stderr, "could not open codec\n");
exit(1);
}

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;
picture->linesize[0] = c->width;
picture->linesize[1] = c->width / 2;
picture->linesize[2] = c->width / 2;

/* encode 1 second of video */
for(i=0;i<25;i++) {
fflush(stdout);
/* prepare a dummy image */
/* Y */
for(y=0;y<c->height;y++) {
for(x=0;x<c->width;x++) {
picture->data[0][y * picture->linesize[0] + x] = x + y + i * 3;
}
}

/* Cb and Cr */
for(y=0;y<c->height/2;y++) {
for(x=0;x<c->width/2;x++) {
picture->data[1][y * picture->linesize[1] + x] = 128 + y + i * 2;
picture->data[2][y * picture->linesize[2] + x] = 64 + x + i * 5;
}
}

/* 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);
}

/* add sequence end code to have a real mpeg file */
outbuf[0] = 0x00;
outbuf[1] = 0x00;
outbuf[2] = 0x01;
outbuf[3] = 0xb7;
fwrite(outbuf, 1, 4, f);
fclose(f);
free(picture_buf);
free(outbuf);

avcodec_close(c);
av_free(c);
av_free(picture);
printf("\n");
}

int main(int argc, char **argv)
{
const char *filename;

/* must be called before using avcodec lib */
avcodec_init();

/* register all the codecs */
avcodec_register_all();

if (argc <= 1) {
video_encode_example("/tmp/test.mpg");
filename = "/tmp/test.mpg";
} else {
filename = argv[1];
}

// audio_decode_example("/tmp/test.sw", filename);
video_decode_example("/tmp/test%d.pgm", filename);

return 0;
}

新手，请多多指点啊，调试了半天也找到是什么原因引起的,我用的是FFmpeg-full-SDK-3.2

[-燕赤侠-]

[Quote=引用 2 楼 SoftSoftSoft2008 的回复:]
这两句执行了？
avcodec_init() ;
avcodec_register_all() ;

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[/Quote]


执行了

[-燕赤侠-]

知道原因了原来是
c->time_base.den = 1;
c->time_base.num = 25; 赋值错误

正确的应该是

c->time_base.den = 25;
c->time_base.num = 1;

[-燕赤侠-]

自己顶一下。

[SoftSoftSoft2008]

这两句执行了？
avcodec_init() ;
avcodec_register_all() ;

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昵 称: CSDN
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E-Mail: [e-mail]

[GoogleGeek]

建议到下面的专业的 FFmpeg讨论组 来咨询！保证在24小时内解决你的问题！

http://groups.google.com/group/nextplayer