mpeg video header parser

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@2566 b3059339-0415-0410-9bf9-f77b7e298cf2

libmpdemux/Makefile

@@ -3,7 +3,7 @@ LIBNAME = libmpdemux.a
 
 include ../config.mak
 
-SRCS = cache2.c asfheader.c aviheader.c aviprint.c aviwrite.c demux_asf.c demux_avi.c demux_mov.c demux_mpg.c demuxer.c dvdauth.c open.c parse_es.c stream.c
+SRCS = mpeg_hdr.c cache2.c asfheader.c aviheader.c aviprint.c aviwrite.c demux_asf.c demux_avi.c demux_mov.c demux_mpg.c demuxer.c dvdauth.c open.c parse_es.c stream.c
 ifeq ($(STREAMING),yes)
 SRCS += asf_streaming.c url.c http.c network.c
 endif

libmpdemux/mpeg_hdr.c

@@ -0,0 +1,100 @@
+
+// based on libmpeg2/header.c by Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
+
+// #include <inttypes.h>
+#include <stdio.h>
+
+#include "config.h"
+#include "mpeg_hdr.h"
+
+static int frameratecode2framerate[16] = {
+  0,
+  // Official mpeg1/2 framerates:
+  24000*10000/1001, 24*10000,25*10000, 30000*10000/1001, 30*10000,50*10000,60000*10000/1001, 60*10000,
+  // libmpeg3's "Unofficial economy rates":
+  1*10000,5*10000,10*10000,12*10000,15*10000,0,0
+};
+
+
+int mp_header_process_sequence_header (mp_mpeg_header_t * picture, unsigned char * buffer)
+{
+    int width, height;
+
+    if ((buffer[6] & 0x20) != 0x20){
+	printf("missing marker bit!\n");
+	return 1;	/* missing marker_bit */
+    }
+
+    height = (buffer[0] << 16) | (buffer[1] << 8) | buffer[2];
+
+    picture->display_picture_width = (height >> 12);
+    picture->display_picture_height = (height & 0xfff);
+
+    width = ((height >> 12) + 15) & ~15;
+    height = ((height & 0xfff) + 15) & ~15;
+
+    if ((width > 768) || (height > 576)){
+	printf("size restrictions for MP@ML or MPEG1 exceeded! (%dx%d)\n",width,height);
+//	return 1;	/* size restrictions for MP@ML or MPEG1 */
+    }
+    
+    picture->aspect_ratio_information = buffer[3] >> 4;
+    picture->frame_rate_code = buffer[3] & 15;
+    picture->fps=frameratecode2framerate[picture->frame_rate_code];
+    picture->bitrate = (buffer[4]<<10)|(buffer[5]<<2)|(buffer[6]>>6);
+    picture->mpeg1 = 1;
+    picture->picture_structure = 3; //FRAME_PICTURE;
+    picture->display_time=100;
+    return 0;
+}
+
+static int header_process_sequence_extension (mp_mpeg_header_t * picture,
+					      unsigned char * buffer)
+{
+    /* check chroma format, size extensions, marker bit */
+    if (((buffer[1] & 0x07) != 0x02) || (buffer[2] & 0xe0) ||
+	((buffer[3] & 0x01) != 0x01))
+	return 1;
+
+    picture->progressive_sequence = (buffer[1] >> 3) & 1;
+    picture->mpeg1 = 0;
+    return 0;
+}
+
+static int header_process_picture_coding_extension (mp_mpeg_header_t * picture, unsigned char * buffer)
+{
+    picture->picture_structure = buffer[2] & 3;
+    picture->top_field_first = buffer[3] >> 7;
+    picture->repeat_first_field = (buffer[3] >> 1) & 1;
+    picture->progressive_frame = buffer[4] >> 7;
+
+    // repeat_first implementation by A'rpi/ESP-team, based on libmpeg3:
+    picture->display_time=100;
+    if(picture->repeat_first_field){
+        if(picture->progressive_sequence){
+            if(picture->top_field_first)
+                picture->display_time+=200;
+            else
+                picture->display_time+=100;
+        } else
+        if(picture->progressive_frame){
+                picture->display_time+=50;
+        }
+    }
+    //temopral hack. We calc time on every field, so if we have 2 fields
+    // interlaced we'll end with double time for 1 frame
+    if( picture->picture_structure!=3 ) picture->display_time/=2;
+    return 0;
+}
+
+int mp_header_process_extension (mp_mpeg_header_t * picture, unsigned char * buffer)
+{
+    switch (buffer[0] & 0xf0) {
+    case 0x10:	/* sequence extension */
+	return header_process_sequence_extension (picture, buffer);
+    case 0x80:	/* picture coding extension */
+	return header_process_picture_coding_extension (picture, buffer);
+    }
+    return 0;
+}
+

libmpdemux/mpeg_hdr.h

@@ -0,0 +1,21 @@
+
+typedef struct {
+    // video info:
+    int mpeg1; // 0=mpeg2  1=mpeg1
+    int display_picture_width;
+    int display_picture_height;
+    int aspect_ratio_information;
+    int frame_rate_code;
+    int fps; // fps*10000
+    int bitrate; // 0x3FFFF==VBR
+    // timing:
+    int picture_structure;
+    int progressive_sequence;
+    int repeat_first_field;
+    int progressive_frame;
+    int top_field_first;
+    int display_time; // secs*100
+} mp_mpeg_header_t;
+
+int mp_header_process_sequence_header (mp_mpeg_header_t * picture, unsigned char * buffer);
+int mp_header_process_extension (mp_mpeg_header_t * picture, unsigned char * buffer);