├── Makefile
├── README.md
└── sei_parser.c


/Makefile:
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1 | all:
2 | 	gcc sei_parser.c -o sei_parser
3 | 
4 | clean:
5 | 	rm sei_parser
6 | 


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/README.md:
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1 | H.264 Supplemental Enhancement Information (SEI) parser
2 | =======================================================
3 | 
4 | Extracts the SEI information of a raw H.264 video stream to check whether the frame_packing flag is set appropriately for 3D stereoscopic video to be detected correctly by players
5 | 
6 | Can be compiled under both Linux and Windows.
7 | 


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/sei_parser.c:
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  1 | /**
  2 |  * Extracts the SEI information of a raw H.264 video stream
  3 |  * to check whether the frame_packing flag is set appropriately
  4 |  * for 3D stereoscopic video to be detected correctly by players
  5 |  * Compilable for Linux and Windows
  6 |  */
  7 | 
  8 | 
  9 | #define _CRT_SECURE_NO_WARNINGS // suppress windows compile warning for insecure fopen calls
 10 | #include <stdlib.h>
 11 | #include <stdio.h>
 12 | 
 13 | int mask[] = {0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01};
 14 | 
 15 | int readBit(unsigned char data[], int* bitpos) {
 16 | 	int bit = (data[*bitpos/8] & mask[*bitpos%8]) != 0 ? 1 : 0;
 17 | 	(*bitpos)++;
 18 | 	return bit;
 19 | }
 20 | 
 21 | long readUnsigned(unsigned char data[], int* bitpos, int length) {
 22 | 	long value = 0;
 23 | 	while (length-->0)
 24 | 		if (readBit(data, bitpos) == 1)
 25 | 			value += 1<<length;
 26 | 	return value;
 27 | }
 28 | 
 29 | long readUExpGolomb(unsigned char data[], int* bitpos) {
 30 | 	int zeros = 0;
 31 | 	while (readBit(data, bitpos) == 0)
 32 | 		zeros++;
 33 | 	return (1<<zeros)-1 + readUnsigned(data, bitpos, zeros);
 34 | }
 35 | 
 36 | void parse_sei_payload(unsigned char payload[], int payload_size) {
 37 | 	int bitpos = 0;
 38 | 	int frame_packing_arrangement_cancel_flag;
 39 | 	long frame_packing_arrangement_type;
 40 | 	int quincunx_sampling_flag;
 41 | 
 42 | 	printf("frame_packing_arrangement_id = %li\n", readUExpGolomb(payload, &bitpos));
 43 | 	frame_packing_arrangement_cancel_flag = readBit(payload, &bitpos);
 44 | 	printf("frame_packing_arrangement_cancel_flag = %i\n", frame_packing_arrangement_cancel_flag);
 45 | 	if (!frame_packing_arrangement_cancel_flag) {
 46 | 		frame_packing_arrangement_type = readUnsigned(payload, &bitpos, 7);
 47 | 		printf("frame_packing_arrangement_type = %li\n", frame_packing_arrangement_type);
 48 | 		quincunx_sampling_flag = readBit(payload, &bitpos);
 49 | 		printf("quincunx_sampling_flag = %i\n", quincunx_sampling_flag);
 50 | 		printf("content_interpretation_type = %li\n", readUnsigned(payload, &bitpos, 6));
 51 | 		printf("spatial_flipping_flag = %i\n", readBit(payload, &bitpos));
 52 | 		printf("frame0_flipped_flag = %i\n", readBit(payload, &bitpos));
 53 | 		printf("field_views_flag = %i\n", readBit(payload, &bitpos));
 54 | 		printf("current_frame_is_frame0_flag = %i\n", readBit(payload, &bitpos));
 55 | 		printf("frame0_self_contained_flag = %i\n", readBit(payload, &bitpos));
 56 | 		printf("frame1_self_contained_flag = %i\n", readBit(payload, &bitpos));
 57 | 		if (!quincunx_sampling_flag && frame_packing_arrangement_type != 5) {
 58 | 			printf("frame0_grid_position_x = %li\n", readUnsigned(payload, &bitpos, 4));
 59 | 			printf("frame0_grid_position_y = %li\n", readUnsigned(payload, &bitpos, 4));
 60 | 			printf("frame1_grid_position_x = %li\n", readUnsigned(payload, &bitpos, 4));
 61 | 			printf("frame1_grid_position_y = %li\n", readUnsigned(payload, &bitpos, 4));
 62 | 		}
 63 | 		printf("frame_packing_arrangement_reserved_byte = %li\n", readUnsigned(payload, &bitpos, 8));
 64 | 		printf("frame_packing_arrangement_repetition_period = %li\n", readUExpGolomb(payload, &bitpos));
 65 | 	}
 66 | 	printf("frame_packing_arrangement_extension_flag = %i\n", readBit(payload, &bitpos));
 67 | 
 68 | 	printf("rbsp trailer: ");
 69 | 	while (bitpos < payload_size*8) {
 70 | 		printf("%i", readBit(payload, &bitpos));
 71 | 		if (bitpos % 8 == 0)
 72 | 			printf(" ");
 73 | 	}
 74 | 	printf("\n");
 75 | }
 76 | 
 77 | void parse_sei_unit(FILE* f) {
 78 | 	int payload_type = 0;
 79 | 	int payload_size = 0;
 80 | 	unsigned char* payload;
 81 | 	int i, emu_count;
 82 | 
 83 | 	printf("found a SEI NAL unit!\n");
 84 | 	while (!feof(f) && payload_type % 0xFF == 0)
 85 | 		payload_type += fgetc(f);
 86 | 	printf("payload_type = %i\n", payload_type);
 87 | 	while (!feof(f) && payload_size % 0xFF == 0)
 88 | 		payload_size += fgetc(f);
 89 | 	printf("payload_size = %i\n", payload_size);
 90 | 
 91 | 	if (payload_type != 45)
 92 | 		return;
 93 | 
 94 | 	payload = (unsigned char*)malloc(payload_size*sizeof(unsigned char));
 95 | 	for (i=0, emu_count=0; i<payload_size && !feof(f); i++, emu_count++) {
 96 | 		payload[i] = fgetc(f);
 97 | 		// drop emulation prevention bytes
 98 | 		if (emu_count>=2 && payload[i] == 0x03 && payload[i-1] == 0x00 && payload[i-2] == 0x00) {
 99 | 			i--;
100 | 			emu_count = 0;
101 | 		}
102 | 	}
103 | 	if (i != payload_size) {
104 | 		fprintf(stderr, "EOF reached while reading SEI payload");
105 | 		free(payload);
106 | 		return;
107 | 	}
108 | 	parse_sei_payload(payload, payload_size);
109 | 	free(payload);
110 | }
111 | 
112 | void seek_sei(char* filename) {
113 | 	int offset = 0;
114 | 	int checklen = 0;
115 | 	FILE* f = fopen(filename, "r");
116 | 	while (!feof(f)) {
117 | 		if (checklen < 2 && fgetc(f) == 0x00)
118 | 			checklen++;
119 | 		else if (checklen == 2 && fgetc(f) == 0x01)
120 | 			checklen++;
121 | 		else if (checklen == 3 && fgetc(f) == 0x06) {
122 | 			parse_sei_unit(f);
123 | 			checklen = 0;
124 | 		}
125 | 		else
126 | 			checklen = 0;
127 | 	}
128 | 	fclose(f);
129 | }
130 | 
131 | int main(int argc, char** args) {
132 | 	if (argc != 2)
133 | 		printf("Usage: sei_parser <h264-file>\n or simply drag&drop a h264-file on this program\n2011-11-03-schiermike\n\n");
134 | 	else
135 | 		seek_sei(args[1]);
136 | 
137 | 	printf("Press any key to quit...\n");
138 | 	getchar();
139 | 
140 | 	return 0;
141 | }
142 | 


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