FFmpeg: libavcodec/cbs_jpeg_syntax_template.c Source File

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libavcodec

cbs_jpeg_syntax_template.c

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1 /*

2 * This file is part of FFmpeg.

3 *

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

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

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

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

8 *

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

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

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

12 * Lesser General Public License for more details.

13 *

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

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

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

17 */

19 static int FUNC(frame_header)(CodedBitstreamContext *ctx, RWContext *rw,

20 JPEGRawFrameHeader *current)

21 {

22 int err, i;

24 HEADER("Frame Header");

26 u(16, Lf, 8, 8 + 3 * JPEG_MAX_COMPONENTS);

28 u(8, P, 2, 16);

29 u(16, Y, 0, JPEG_MAX_HEIGHT);

30 u(16, X, 1, JPEG_MAX_WIDTH);

31 u(8, Nf, 1, JPEG_MAX_COMPONENTS);

33 for (i = 0; i < current->Nf; i++) {

34 us(8, C[i], i, 0, JPEG_MAX_COMPONENTS);

35 us(4, H[i], i, 1, 4);

36 us(4, V[i], i, 1, 4);

37 us(8, Tq[i], i, 0, 3);

38 }

40 return 0;

41 }

43 static int FUNC(quantisation_table)(CodedBitstreamContext *ctx, RWContext *rw,

44 JPEGRawQuantisationTable *current)

45 {

46 int err, i;

48 u(4, Pq, 0, 1);

49 u(4, Tq, 0, 3);

51 if (current->Pq) {

52 for (i = 0; i < 64; i++)

53 us(16, Q[i], i, 1, 255);

54 } else {

55 for (i = 0; i < 64; i++)

56 us(8, Q[i], i, 1, 255);

57 }

59 return 0;

60 }

62 static int FUNC(dqt)(CodedBitstreamContext *ctx, RWContext *rw,

63 JPEGRawQuantisationTableSpecification *current)

64 {

65 int err, i, n;

67 HEADER("Quantisation Tables");

69 u(16, Lq, 2, 2 + 4 * 65);

70 n = current->Lq / 65;

72 for (i = 0; i < n; i++)

73 CHECK(FUNC(quantisation_table)(ctx, rw, &current->table[i]));

75 return 0;

76 }

78 static int FUNC(huffman_table)(CodedBitstreamContext *ctx, RWContext *rw,

79 JPEGRawHuffmanTable *current)

80 {

81 int err, i, j, ij;

83 u(4, Tc, 0, 1);

84 u(4, Th, 0, 3);

86 for (i = 0; i < 16; i++)

87 us(8, L[i], i, 0, 255);

89 ij = 0;

90 for (i = 0; i < 16; i++) {

91 for (j = 0; j < current->L[i]; j++) {

92 if (ij >= FF_ARRAY_ELEMS(current->V))

93 return AVERROR_INVALIDDATA;

94 us(8, V[ij], ij, 0, 255);

95 ++ij;

96 }

97 }

99 return 0;

100 }

101

102 static int FUNC(dht)(CodedBitstreamContext *ctx, RWContext *rw,

103 JPEGRawHuffmanTableSpecification *current)

104 {

105 int err, i, j, n;

106

107 HEADER("Huffman Tables");

108

109 u(16, Lh, 2, 2 + 8 * (1 + 16 + 256));

110

111 n = 2;

112 for (i = 0; n < current->Lh; i++) {

113 if (i >= 8)

114 return AVERROR_INVALIDDATA;

115

116 CHECK(FUNC(huffman_table)(ctx, rw, &current->table[i]));

117

118 ++n;

119 for (j = 0; j < 16; j++)

120 n += 1 + current->table[i].L[j];

121 }

122

123 return 0;

124 }

125

126 static int FUNC(scan_header)(CodedBitstreamContext *ctx, RWContext *rw,

127 JPEGRawScanHeader *current)

128 {

129 int err, j;

130

131 HEADER("Scan");

132

133 u(16, Ls, 6, 6 + 2 * JPEG_MAX_COMPONENTS);

134

135 u(8, Ns, 1, 4);

136 for (j = 0; j < current->Ns; j++) {

137 us(8, Cs[j], j, 0, JPEG_MAX_COMPONENTS);

138 us(4, Td[j], j, 0, 3);

139 us(4, Ta[j], j, 0, 3);

140 }

141

142 u(8, Ss, 0, 63);

143 u(8, Se, 0, 63);

144 u(4, Ah, 0, 13);

145 u(4, Al, 0, 15);

146

147 return 0;

148 }

149

150 static int FUNC(application_data)(CodedBitstreamContext *ctx, RWContext *rw,

151 JPEGRawApplicationData *current)

152 {

153 int err, i;

154

155 HEADER("Application Data");

156

157 u(16, Lp, 2, 65535);

158

159 if (current->Lp > 2) {

160 #ifdef READ

161 current->Ap_ref = av_buffer_alloc(current->Lp - 2);

162 if (!current->Ap_ref)

163 return AVERROR(ENOMEM);

164 current->Ap = current->Ap_ref->data;

165 #endif

166

167 for (i = 0; i < current->Lp - 2; i++)

168 us(8, Ap[i], i, 0, 255);

169 }

170

171 return 0;

172 }

173

174 static int FUNC(comment)(CodedBitstreamContext *ctx, RWContext *rw,

175 JPEGRawComment *current)

176 {

177 int err, i;

178

179 HEADER("Comment");

180

181 u(16, Lc, 2, 65535);

182

183 if (current->Lc > 2) {

184 #ifdef READ

185 current->Cm_ref = av_buffer_alloc(current->Lc - 2);

186 if (!current->Cm_ref)

187 return AVERROR(ENOMEM);

188 current->Cm = current->Cm_ref->data;

189 #endif

190

191 for (i = 0; i < current->Lc - 2; i++)

192 us(8, Cm[i], i, 0, 255);

193 }

194

195 return 0;

196 }

AVERROR

Filter the word "frame" indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions

#define u(width, name, range_min, range_max)

Definition: cbs_h2645.c:250

HEADER

#define HEADER(name)

Definition: cbs_av1.c:456

CodedBitstreamContext

Context structure for coded bitstream operations.

Definition: cbs.h:219

application_data

static int FUNC() application_data(CodedBitstreamContext *ctx, RWContext *rw, JPEGRawApplicationData *current)

Definition: cbs_jpeg_syntax_template.c:150

JPEG_MAX_WIDTH

@ JPEG_MAX_WIDTH

Definition: cbs_jpeg.h:49

#define Q(x)

Definition: vvc_filter_template.c:433

JPEGRawQuantisationTable

Definition: cbs_jpeg.h:87

CHECK

CHECK(-1) CHECK(-2) }} }} CHECK(1) CHECK(2) }} }} } if(diff0+diff1 > 0) temp -

JPEGRawQuantisationTableSpecification

Definition: cbs_jpeg.h:93

#define us(width, name, range_min, range_max, subs,...)

Definition: cbs_h2645.c:262

s EdgeDetect Foobar g libavfilter vf_edgedetect c libavfilter vf_foobar c edit libavfilter and add an entry for foobar following the pattern of the other filters edit libavfilter allfilters and add an entry for foobar following the pattern of the other filters configure make j< whatever > ffmpeg ffmpeg i you should get a foobar png with Lena edge detected That s your new playground is ready Some little details about what s going which in turn will define variables for the build system and the C

Definition: writing_filters.txt:58

scan_header

static int FUNC() scan_header(CodedBitstreamContext *ctx, RWContext *rw, JPEGRawScanHeader *current)

Definition: cbs_jpeg_syntax_template.c:126

FF_ARRAY_ELEMS

#define FF_ARRAY_ELEMS(a)

Definition: sinewin_tablegen.c:29

ctx

AVFormatContext * ctx

Definition: movenc.c:48

#define V

Definition: avdct.c:30