Code Coverage Report for src/decode/packet.h

1 /*

2 * libnogg: a decoder library for Ogg Vorbis streams

3 * Copyright (c) 2014-2024 Andrew Church <achurch@achurch.org>

4 *

5 * This software may be copied and redistributed under certain conditions;

6 * see the file "COPYING" in the source code distribution for details.

7 * NO WARRANTY is provided with this software.

8 */

9

10 #ifndef NOGG_SRC_DECODE_PACKET_H

11 #define NOGG_SRC_DECODE_PACKET_H

12

13 /*************************************************************************/

14 /*************************************************************************/

15

16 /* Constant returned from get8_packet_raw() when trying to read past the

17 * end of a packet. */

18 #define EOP (-1)

19

20 /* Flag bits set in the page_flag field of the decoder handle based on the

21 * status of the current page. */

22 #define PAGEFLAG_continued_packet 1

23 #define PAGEFLAG_first_page 2

24 #define PAGEFLAG_last_page 4

25

26 /*-----------------------------------------------------------------------*/

27

28 /**

29 * next_segment: Advance to the next segment in the current packet.

30 *

31 * [Parameters]

32 * handle: Stream handle.

33 * [Return value]

34 * True on success, false on error or end of packet.

35 */

36 #define next_segment INTERNAL(next_segment)

37 extern bool next_segment(stb_vorbis *handle);

38

39 /**

40 * reset_page: Reset the current stream state to start reading from a new

41 * page. A call to this function should be followed by a call to start_page()

42 * or start_packet().

43 *

44 * [Parameters]

45 * handle: Stream handle.

46 */

47 #define reset_page INTERNAL(reset_page)

48 extern void reset_page(stb_vorbis *handle);

49

50 /**

51 * start_page: Verify that the stream read position is at the beginning

52 * of a valid Ogg page, and start reading from the page.

53 *

54 * On error, some bytes may have been consumed from the stream.

55 *

56 * [Parameters]

57 * handle: Stream handle.

58 * check_page_number: True to check the page number for sequentiality,

59 * false to skip the check.

60 * [Return value]

61 * True on success, false on error.

62 */

63 #define start_page INTERNAL(start_page)

64 extern bool start_page(stb_vorbis *handle, bool check_page_number);

65

66 /**

67 * start_packet: Start reading a new packet at the current stream read

68 * position, advancing to a new page if necessary. Invalid for packet

69 * mode decoders.

70 *

71 * [Parameters]

72 * handle: Stream handle.

73 * [Return value]

74 * True on success, false on error.

75 */

76 #define start_packet INTERNAL(start_packet)

77 extern bool start_packet(stb_vorbis *handle);

78

79 /**

80 * start_packet_direct: Start reading a new packet from the given data

81 * buffer. Only valid for packet mode decoders.

82 *

83 * [Parameters]

84 * handle: Stream handle.

85 * [Return value]

86 * True on success, false on error.

87 */

88 #define start_packet_direct INTERNAL(start_packet_direct)

89 extern void start_packet_direct(stb_vorbis *handle, const void *packet,

90 int32_t packet_len);

91

92 /**

93 * get8_packet: Read one byte from the current packet. The bit accumulator

94 * for bitstream reads is cleared.

95 *

96 * [Parameters]

97 * handle: Stream handle.

98 * [Return value]

99 * Byte read, or EOP on end of packet or error.

100 */

101 #define get8_packet INTERNAL(get8_packet)

102 extern int get8_packet(stb_vorbis *handle);

103

104 /**

105 * get32_packet: Read a byte-aligned 32-bit signed integer from the

106 * current packet. The bit accumulator for bitstream reads is cleared.

107 *

108 * This function does not check for end-of-packet.

109 *

110 * [Parameters]

111 * handle: Stream handle.

112 * [Return value]

113 * Value read.

114 */

115 #define get32_packet INTERNAL(get32_packet)

116 extern int32_t get32_packet(stb_vorbis *handle);

117

118 /**

119 * getn_packet: Read a sequence of bytes from the current packet. The bit

120 * accumulator for bitstream reads is cleared.

121 *

122 * [Parameters]

123 * handle: Stream handle.

124 * [Return value]

125 * True on success, false on end of packet or error.

126 */

127 #define getn_packet INTERNAL(getn_packet)

128 extern bool getn_packet(stb_vorbis *handle, void *buf, int len);

129

130 /**

131 * get_bits: Read a value of arbitrary bit length from the stream.

132 *

133 * [Parameters]

134 * handle: Stream handle.

135 * [Return value]

136 * Value read, or 0 on end of packet or error.

137 */

138 #define get_bits INTERNAL(get_bits)

139 extern uint32_t get_bits(stb_vorbis *handle, int count);

140

141 /**

142 * flush_packet: Advance the stream read position to the end of the

143 * current packet.

144 *

145 * [Parameters]

146 * handle: Stream handle.

147 * [Return value]

148 * False on unexpected end-of-file, true otherwise.

149 */

150 #define flush_packet INTERNAL(flush_packet)

151 extern bool flush_packet(stb_vorbis *handle);

152

153 /*-----------------------------------------------------------------------*/

154

155 /**

156 * get8_packet_raw: Read one byte from the current packet.

157 *

158 * [Parameters]

159 * handle: Stream handle.

160 * [Return value]

161 * Byte read, or EOP on end of packet or error.

162 */

164 {

168 }

169 }

171 }

172

173 /**

174 * fill_bits: Fill the bit accumulator with as much data as possible.

175 *

176 * [Parameters]

177 * handle: Stream handle.

178 */

179 static inline UNUSED void fill_bits(stb_vorbis *handle)

180 {

181 if (handle->valid_bits == 0) {

182 handle->acc = 0;

183 }

184 while (handle->valid_bits <= ((int)sizeof(long) * 8 - 8)) {

185 const int32_t byte = get8_packet_raw(handle);

186 if (UNLIKELY(byte == EOP)) {

187 break;

188 }

189 handle->acc |= (unsigned long)byte << handle->valid_bits;

190 handle->valid_bits += 8;

191 }

192 }

193

194 /*************************************************************************/

195 /*************************************************************************/

196

197 #endif // NOGG_SRC_DECODE_PACKET_H