Audio and video streams: ffplay: tutorial01

Original:

Http://blog.chinaunix.net/uid-24203478-id-3035890.html

 

The version used is FFMPEG 0.6.3.

Use the compilation command:
Gcc-O tutorial01 tutorial01.c-lavutil-lavformat-lavcodec-lswscale

The source program is as follows:

[CPP]
View plaincopy

1. # Include <libavcodec/avcodec. h>
2. # Include <libavformat/avformat. h>
3. # Include <libswscale/swscale. h>
5. # Include <stdio. h>
7. # Define debug () fprintf (stderr, "% s # % I \ n" ,__ func __,__ line __)
9. Static struct swscontext * img_convert_ctx;
11. Void saveframe (avframe * pframe, int width, int height, int IFRAME)
12. {
13. File * pfile;
14. Char szfilename [32];
15. Int y;
17. Sprintf (szfilename, "frame % d. ppm", IFRAME );
18. Pfile = fopen (szfilename, "WB ");
19. If (pfile = NULL ){
20. Return;
21. }
23. Fprintf (pfile, "P6 \ n % d \ n255 \ n", width, height );
25. For (y = 0; y
26. Fwrite (pframe-> data [0] + y * pframe-> linesize [0], 1, width * 3, pfile );
27. }
29. Fclose (pfile );
30. }
32. Int main (INT argc, char * argv [])
33. {
34. Avformatcontext * pformatctx;
35. Int I, videostream;
36. Avcodeccontext * pcodecctx;
37. Avcodec * pcodec;
38. Avframe * pframe;
39. Avframe * pframergb;
40. Avpacket packet;
41. Int framefinished;
42. Int numbytes;
43. Uint8_t * buffer;
45. If (argc <2 ){
46. Printf ("Please provide a movie file \ n ");
47. Return-1;
48. }
49. Fprintf (stderr, "Arg OK. \ n ");
50. Debug ();
51. Av_register_all ();
52. Fprintf (stderr, "av_register_all () OK. \ n ");
53. Debug ();
55. Pformatctx = avformat_alloc_context (); // allocate space
56. Fprintf (stderr, "avformat_alloc_context () OK. \ n ");
57. Debug ();
58. If (av_open_input_file (& pformatctx, argv [1], null, 0, null )! = 0 ){
59. // If (avformat_open_input (& pformatctx, argv [1], null, null )! = 0) {// open the input file
60. Return-1;
61. }
62. Fprintf (stderr, "avformat_open_input () OK. \ n ");
63. Debug ();
65. If (av_find_stream_info (pformatctx) <0 ){
66. Return-1;
67. }
68. Fprintf (stderr, "av_find_stream_info () OK. \ n ");
69. Debug ();
71. Dump_format (pformatctx, 0, argv [1], 0 );
72. Fprintf (stderr, "dump_format () OK. \ n ");
74. Debug ();
75. Videostream =-1;
76. For (I = 0; I <pformatctx-> nb_streams; I ++ ){
77. If (pformatctx-> streams [I]-> codec-> codec_type = codec_type_video ){
78. Videostream = I;
79. Break;
80. }
81. }
82. Fprintf (stderr, "Find codec_type_video OK. \ n ");
83. Debug ();
84. If (videostream =-1 ){
85. Return-1;
86. }
87. Debug ();
88. Pcodecctx = pformatctx-> streams [videostream]-> codec;
89. Img_convert_ctx = sws_getcontext (
90. Pcodecctx-> width,
91. Pcodecctx-> height,
92. Pcodecctx-> pix_fmt,
93. Pcodecctx-> width,
94. Pcodecctx-> height,
95. Pix_fmt_rgb24,
96. Sws_bicubic,
97. Null, null, null );
98. Fprintf (stderr, "sws_getcontext () OK. \ n ");
100. Debug ();
101. Pcodec = avcodec_find_decoder (pcodecctx-> codec_id );
102. If (pcodec = NULL ){
103. Fprintf (stderr, "unsupported codec! \ N ");
104. Return-1;
105. }
106. Fprintf (stderr, "avcodec_find_decoder () OK. \ n ");
108. Debug ();
109. If (avcodec_open (pcodecctx, pcodec) <0 ){
110. Return-1;
111. }
112. Fprintf (stderr, "avcodec_open () OK. \ n ");
113. Debug ();
115. Pframe = avcodec_alloc_frame ();
116. Fprintf (stderr, "avcodec_alloc_frame () OK. \ n ");
117. Debug ();
119. Pframergb = avcodec_alloc_frame ();
120. If (pframergb = NULL ){
121. Return-1;
122. }
123. Fprintf (stderr, "avcodec_alloc_frame () OK. \ n ");
124. Debug ();
126. Numbytes = avpicture_get_size (pix_fmt_rgb24, pcodecctx-> width,
127. Pcodecctx-> height );
128. Fprintf (stderr, "avpicture_get_size () OK. \ n ");
129. Debug ();
130. Buffer = (uint8_t *) av_malloc (numbytes * sizeof (uint8_t ));
132. Debug ();
133. Avpicture_fill (avpicture *) pframergb, buffer, pix_fmt_rgb24,
134. Pcodecctx-> width, pcodecctx-> height );
135. Fprintf (stderr, "avpicture_fill () OK. \ n ");
136. Debug (); I = 0;
137. While (av_read_frame (pformatctx, & Packet)> = 0 ){
138. If (packet. stream_index = videostream ){
139. Avcodec_decode_video (pcodecctx, pframe,
140. & Framefinished,
141. Packet. Data,
142. Packet. size );
143. If (framefinished ){
144. Sws_scale (img_convert_ctx,
145. (Const uint8_t **) pframe-> data,
146. Pframe-> linesize, 0,
147. Pcodecctx-> height,
148. Pframergb-> data,
149. Pframergb-> linesize );
150. If (++ I <= 5 ){
151. Saveframe (pframergb, pcodecctx-> width, pcodecctx-> height, I );
152. }
153. }
154. }
155. Av_free_packet (& Packet );
156. }
157. Debug ();
159. Av_free (buffer );
160. Av_free (pframergb );
162. Av_free (pframe );
164. Avcodec_close (pcodecctx );
166. Av_close_input_file (pformatctx );
168. Return 0;
169. }