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authorarpi <arpi@b3059339-0415-0410-9bf9-f77b7e298cf2>2001-10-30 18:45:54 +0000
committerarpi <arpi@b3059339-0415-0410-9bf9-f77b7e298cf2>2001-10-30 18:45:54 +0000
commitf395431b7d01ed9c311fc53a458eb0434e037936 (patch)
tree2dd785d676daf8d1ea572cf374a2d9e915f25984 /libmpdemux/mpeg_hdr.c
parent6b0ee0f3c362910bccb1aa7d51b58a3c70029f87 (diff)
downloadmpv-f395431b7d01ed9c311fc53a458eb0434e037936.tar.bz2
mpv-f395431b7d01ed9c311fc53a458eb0434e037936.tar.xz
mpeg video header parser
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@2566 b3059339-0415-0410-9bf9-f77b7e298cf2
Diffstat (limited to 'libmpdemux/mpeg_hdr.c')
-rw-r--r--libmpdemux/mpeg_hdr.c100
1 files changed, 100 insertions, 0 deletions
diff --git a/libmpdemux/mpeg_hdr.c b/libmpdemux/mpeg_hdr.c
new file mode 100644
index 0000000000..780a5fbfaf
--- /dev/null
+++ b/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;
+}
+