FFmpeg: libavcodec/tak.c Source File

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libavcodec

tak.c

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1 /*

2 * TAK common code

4 *

5 * This file is part of FFmpeg.

6 *

7 * FFmpeg is free software; you can redistribute it and/or

8 * modify it under the terms of the GNU Lesser General Public

9 * License as published by the Free Software Foundation; either

10 * version 2.1 of the License, or (at your option) any later version.

11 *

12 * FFmpeg is distributed in the hope that it will be useful,

13 * but WITHOUT ANY WARRANTY; without even the implied warranty of

14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

15 * Lesser General Public License for more details.

16 *

17 * You should have received a copy of the GNU Lesser General Public

18 * License along with FFmpeg; if not, write to the Free Software

19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

20 */

22 #include "libavutil/crc.h"

23 #include "libavutil/intreadwrite.h"

24 #include "tak.h"

26 static const int64_t tak_channel_layouts[] = {

27 0,

28 AV_CH_FRONT_LEFT,

29 AV_CH_FRONT_RIGHT,

30 AV_CH_FRONT_CENTER,

31 AV_CH_LOW_FREQUENCY,

32 AV_CH_BACK_LEFT,

33 AV_CH_BACK_RIGHT,

34 AV_CH_FRONT_LEFT_OF_CENTER,

35 AV_CH_FRONT_RIGHT_OF_CENTER,

36 AV_CH_BACK_CENTER,

37 AV_CH_SIDE_LEFT,

38 AV_CH_SIDE_RIGHT,

39 AV_CH_TOP_CENTER,

40 AV_CH_TOP_FRONT_LEFT,

41 AV_CH_TOP_FRONT_CENTER,

42 AV_CH_TOP_FRONT_RIGHT,

43 AV_CH_TOP_BACK_LEFT,

44 AV_CH_TOP_BACK_CENTER,

45 AV_CH_TOP_BACK_RIGHT,

46 };

48 static const uint16_t frame_duration_type_quants[] = {

49 3, 4, 6, 8, 4096, 8192, 16384, 512, 1024, 2048,

50 };

52 static int tak_get_nb_samples(int sample_rate, enum TAKFrameSizeType type)

53 {

54 int nb_samples, max_nb_samples;

56 if (type <= TAK_FST_250ms) {

57 nb_samples = sample_rate * frame_duration_type_quants[type] >>

58 TAK_FRAME_DURATION_QUANT_SHIFT;

59 max_nb_samples = 16384;

60 } else if (type < FF_ARRAY_ELEMS(frame_duration_type_quants)) {

61 nb_samples = frame_duration_type_quants[type];

62 max_nb_samples = sample_rate *

63 frame_duration_type_quants[TAK_FST_250ms] >>

64 TAK_FRAME_DURATION_QUANT_SHIFT;

65 } else {

66 return AVERROR_INVALIDDATA;

67 }

69 if (nb_samples <= 0 || nb_samples > max_nb_samples)

70 return AVERROR_INVALIDDATA;

72 return nb_samples;

73 }

75 static int crc_init = 0;

76 #if CONFIG_SMALL

77 #define CRC_TABLE_SIZE 257

78 #else

79 #define CRC_TABLE_SIZE 1024

80 #endif

81 static AVCRC crc_24[CRC_TABLE_SIZE];

83 av_cold void ff_tak_init_crc(void)

84 {

85 if (!crc_init) {

86 av_crc_init(crc_24, 0, 24, 0x864CFBU, sizeof(crc_24));

87 crc_init = 1;

88 }

89 }

91 int ff_tak_check_crc(const uint8_t *buf, unsigned int buf_size)

92 {

93 uint32_t crc, CRC;

95 if (buf_size < 4)

96 return AVERROR_INVALIDDATA;

97 buf_size -= 3;

99 CRC = AV_RB24(buf + buf_size);

100 crc = av_crc(crc_24, 0xCE04B7U, buf, buf_size);

101 if (CRC != crc)

102 return AVERROR_INVALIDDATA;

103

104 return 0;

105 }

106

107 void avpriv_tak_parse_streaminfo(GetBitContext *gb, TAKStreamInfo *s)

108 {

109 uint64_t channel_mask = 0;

110 int frame_type, i;

111

112 s->codec = get_bits(gb, TAK_ENCODER_CODEC_BITS);

113 skip_bits(gb, TAK_ENCODER_PROFILE_BITS);

114

115 frame_type = get_bits(gb, TAK_SIZE_FRAME_DURATION_BITS);

116 s->samples = get_bits64(gb, TAK_SIZE_SAMPLES_NUM_BITS);

117

118 s->data_type = get_bits(gb, TAK_FORMAT_DATA_TYPE_BITS);

119 s->sample_rate = get_bits(gb, TAK_FORMAT_SAMPLE_RATE_BITS) +

120 TAK_SAMPLE_RATE_MIN;

121 s->bps = get_bits(gb, TAK_FORMAT_BPS_BITS) +

122 TAK_BPS_MIN;

123 s->channels = get_bits(gb, TAK_FORMAT_CHANNEL_BITS) +

124 TAK_CHANNELS_MIN;

125

126 if (get_bits1(gb)) {

127 skip_bits(gb, TAK_FORMAT_VALID_BITS);

128 if (get_bits1(gb)) {

129 for (i = 0; i < s->channels; i++) {

130 int value = get_bits(gb, TAK_FORMAT_CH_LAYOUT_BITS);

131

132 if (value < FF_ARRAY_ELEMS(tak_channel_layouts))

133 channel_mask |= tak_channel_layouts[value];

134 }

135 }

136 }

137

138 s->ch_layout = channel_mask;

139 s->frame_samples = tak_get_nb_samples(s->sample_rate, frame_type);

140 }

141

142 int ff_tak_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb,

143 TAKStreamInfo *ti, int log_level_offset)

144 {

145 if (get_bits(gb, TAK_FRAME_HEADER_SYNC_ID_BITS) != TAK_FRAME_HEADER_SYNC_ID) {

146 av_log(avctx, AV_LOG_ERROR + log_level_offset, "missing sync id\n");

147 return AVERROR_INVALIDDATA;

148 }

149

150 ti->flags = get_bits(gb, TAK_FRAME_HEADER_FLAGS_BITS);

151 ti->frame_num = get_bits(gb, TAK_FRAME_HEADER_NO_BITS);

152

153 if (ti->flags & TAK_FRAME_FLAG_IS_LAST) {

154 ti->last_frame_samples = get_bits(gb, TAK_FRAME_HEADER_SAMPLE_COUNT_BITS) + 1;

155 skip_bits(gb, 2);

156 } else {

157 ti->last_frame_samples = 0;

158 }

159

160 if (ti->flags & TAK_FRAME_FLAG_HAS_INFO) {

161 avpriv_tak_parse_streaminfo(gb, ti);

162

163 if (get_bits(gb, 6))

164 skip_bits(gb, 25);

165 align_get_bits(gb);

166 }

167

168 if (ti->flags & TAK_FRAME_FLAG_HAS_METADATA)

169 return AVERROR_INVALIDDATA;

170

171 skip_bits(gb, 24);

172

173 return 0;

174 }

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