X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=output_example.c;h=45f6a0645b70c593949f29287315848515b342ed;hb=14e2a9404e25ffd80e84b1b7a152858c63b2d690;hp=0e06b0cbb619246b7e18821a8d8323fabfd70f2a;hpb=e70fcf075b8f92c4e410b80c703fbdc1d531d42d;p=ffmpeg

diff --git a/output_example.c b/output_example.c
index 0e06b0cbb61..45f6a0645b7 100644
--- a/output_example.c
+++ b/output_example.c
@@ -24,13 +24,19 @@
  */
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
 #include <math.h>
 
+#ifndef M_PI
+#define M_PI 3.1415926535897931
+#endif
+
 #include "avformat.h"
 
 /* 5 seconds stream duration */
-#define STREAM_DURATION 5.0
-
+#define STREAM_DURATION   5.0
+#define STREAM_FRAME_RATE 25 /* 25 images/s */
+#define STREAM_NB_FRAMES  ((int)(STREAM_DURATION * STREAM_FRAME_RATE))
 
 /**************************************************************/
 /* audio output */
@@ -115,21 +121,33 @@ void open_audio(AVFormatContext *oc, AVStream *st)
     samples = malloc(audio_input_frame_size * 2 * c->channels);
 }
 
+/* prepare a 16 bit dummy audio frame of 'frame_size' samples and
+   'nb_channels' channels */
+void get_audio_frame(int16_t *samples, int frame_size, int nb_channels)
+{
+    int j, i, v;
+    int16_t *q;
+
+    q = samples;
+    for(j=0;j<frame_size;j++) {
+        v = (int)(sin(t) * 10000);
+        for(i = 0; i < nb_channels; i++)
+            *q++ = v;
+        t += tincr;
+        tincr += tincr2;
+    }
+}
+
 void write_audio_frame(AVFormatContext *oc, AVStream *st)
 {
-    int j, out_size;
+    int out_size;
     AVCodecContext *c;
 
 
     c = &st->codec;
 
-    for(j=0;j<audio_input_frame_size;j++) {
-        samples[2*j] = (int)(sin(t) * 10000);
-        samples[2*j+1] = samples[2*j];
-        t += tincr;
-        tincr += tincr2;
-    }
-    
+    get_audio_frame(samples, audio_input_frame_size, c->channels);
+
     out_size = avcodec_encode_audio(c, audio_outbuf, audio_outbuf_size, samples);
 
     /* write the compressed frame in the media file */
@@ -176,10 +194,23 @@ AVStream *add_video_stream(AVFormatContext *oc, int codec_id)
     c->width = 352;  
     c->height = 288;
     /* frames per second */
-    c->frame_rate = 25;  
-    c->frame_rate_base= 1;
-    c->gop_size = 12; /* emit one intra frame every twelve frames */
-
+    c->frame_rate = STREAM_FRAME_RATE;  
+    c->frame_rate_base = 1;
+    c->gop_size = 12; /* emit one intra frame every twelve frames at most */
+    if (c->codec_id == CODEC_ID_MPEG2VIDEO) {
+        /* just for testing, we also add B frames */
+        c->max_b_frames = 2;
+    }
+    if (c->codec_id == CODEC_ID_MPEG1VIDEO){
+        /* needed to avoid using macroblocks in which some coeffs overflow 
+           this doesnt happen with normal video, it just happens here as the 
+           motion of the chroma plane doesnt match the luma plane */
+        c->mb_decision=2;
+    }
+    // some formats want stream headers to be seperate
+    if(!strcmp(oc->oformat->name, "mp4") || !strcmp(oc->oformat->name, "mov") || !strcmp(oc->oformat->name, "3gp"))
+        c->flags |= CODEC_FLAG_GLOBAL_HEADER;
+    
     return st;
 }
 
@@ -278,18 +309,27 @@ void write_video_frame(AVFormatContext *oc, AVStream *st)
 {
     int out_size, ret;
     AVCodecContext *c;
-
+    AVFrame *picture_ptr;
+    
     c = &st->codec;
     
-    if (c->pix_fmt != PIX_FMT_YUV420P) {
-        /* as we only generate a YUV420P picture, we must convert it
-           to the codec pixel format if needed */
-        fill_yuv_image(tmp_picture, frame_count, c->width, c->height);
-        img_convert((AVPicture *)picture, c->pix_fmt, 
-                    (AVPicture *)tmp_picture, PIX_FMT_YUV420P,
-                    c->width, c->height);
+    if (frame_count >= STREAM_NB_FRAMES) {
+        /* no more frame to compress. The codec has a latency of a few
+           frames if using B frames, so we get the last frames by
+           passing a NULL picture */
+        picture_ptr = NULL;
     } else {
-        fill_yuv_image(picture, frame_count, c->width, c->height);
+        if (c->pix_fmt != PIX_FMT_YUV420P) {
+            /* as we only generate a YUV420P picture, we must convert it
+               to the codec pixel format if needed */
+            fill_yuv_image(tmp_picture, frame_count, c->width, c->height);
+            img_convert((AVPicture *)picture, c->pix_fmt, 
+                        (AVPicture *)tmp_picture, PIX_FMT_YUV420P,
+                        c->width, c->height);
+        } else {
+            fill_yuv_image(picture, frame_count, c->width, c->height);
+        }
+        picture_ptr = picture;
     }
 
     
@@ -297,13 +337,18 @@ void write_video_frame(AVFormatContext *oc, AVStream *st)
         /* raw video case. The API will change slightly in the near
            futur for that */
         ret = av_write_frame(oc, st->index, 
-                       (uint8_t *)picture, sizeof(AVPicture));
+                       (uint8_t *)picture_ptr, sizeof(AVPicture));
     } else {
         /* encode the image */
-        out_size = avcodec_encode_video(c, video_outbuf, video_outbuf_size, picture);
-        
-        /* write the compressed frame in the media file */
-        ret = av_write_frame(oc, st->index, video_outbuf, out_size);
+        out_size = avcodec_encode_video(c, video_outbuf, video_outbuf_size, picture_ptr);
+        /* if zero size, it means the image was buffered */
+        if (out_size != 0) {
+            /* write the compressed frame in the media file */
+            /* XXX: in case of B frames, the pts is not yet valid */
+            ret = av_write_frame(oc, st->index, video_outbuf, out_size);
+        } else {
+            ret = 0;
+        }
     }
     if (ret != 0) {
         fprintf(stderr, "Error while writing video frame\n");
@@ -363,7 +408,7 @@ int main(int argc, char **argv)
     }
     
     /* allocate the output media context */
-    oc = av_mallocz(sizeof(AVFormatContext));
+    oc = av_alloc_format_context();
     if (!oc) {
         fprintf(stderr, "Memory error\n");
         exit(1);