FFmpeg: libavcodec/indeo2.c Source File

FFmpeg

[フレーム]

libavcodec

indeo2.c

Go to the documentation of this file.

1 /*

2 * Intel Indeo 2 codec

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 /**

23 * @file

24 * Intel Indeo 2 decoder.

25 */

27 #include "libavutil/attributes.h"

28 #include "libavutil/thread.h"

30 #define BITSTREAM_READER_LE

31 #include "avcodec.h"

32 #include "codec_internal.h"

33 #include "get_bits.h"

34 #include "indeo2data.h"

35 #include "internal.h"

36 #include "mathops.h"

38 typedef struct Ir2Context{

39 AVCodecContext *avctx;

40 AVFrame *picture;

41 GetBitContext gb;

42 int decode_delta;

43 } Ir2Context;

45 #define CODE_VLC_BITS 14

46 static VLC ir2_vlc;

48 /* Indeo 2 codes are in range 0x01..0x7F and 0x81..0x90 */

49 static inline int ir2_get_code(GetBitContext *gb)

50 {

51 return get_vlc2(gb, ir2_vlc.table, CODE_VLC_BITS, 1);

52 }

54 static int ir2_decode_plane(Ir2Context *ctx, int width, int height, uint8_t *dst,

55 int pitch, const uint8_t *table)

56 {

57 int i;

58 int j;

59 int out = 0;

61 if ((width & 1) || width * height / (2*(IR2_CODES - 0x7F)) > get_bits_left(&ctx->gb))

62 return AVERROR_INVALIDDATA;

64 /* first line contain absolute values, other lines contain deltas */

65 while (out < width) {

66 int c = ir2_get_code(&ctx->gb);

67 if (c >= 0x80) { /* we have a run */

68 c -= 0x7F;

69 if (out + c*2 > width)

70 return AVERROR_INVALIDDATA;

71 for (i = 0; i < c * 2; i++)

72 dst[out++] = 0x80;

73 } else { /* copy two values from table */

74 if (c <= 0)

75 return AVERROR_INVALIDDATA;

76 dst[out++] = table[c * 2];

77 dst[out++] = table[(c * 2) + 1];

78 }

79 }

80 dst += pitch;

82 for (j = 1; j < height; j++) {

83 out = 0;

84 while (out < width) {

85 int c;

86 if (get_bits_left(&ctx->gb) <= 0)

87 return AVERROR_INVALIDDATA;

88 c = ir2_get_code(&ctx->gb);

89 if (c >= 0x80) { /* we have a skip */

90 c -= 0x7F;

91 if (out + c*2 > width)

92 return AVERROR_INVALIDDATA;

93 for (i = 0; i < c * 2; i++) {

94 dst[out] = dst[out - pitch];

95 out++;

96 }

97 } else { /* add two deltas from table */

98 int t;

99 if (c <= 0)

100 return AVERROR_INVALIDDATA;

101 t = dst[out - pitch] + (table[c * 2] - 128);

102 t = av_clip_uint8(t);

103 dst[out] = t;

104 out++;

105 t = dst[out - pitch] + (table[(c * 2) + 1] - 128);

106 t = av_clip_uint8(t);

107 dst[out] = t;

108 out++;

109 }

110 }

111 dst += pitch;

112 }

113 return 0;

114 }

115

116 static int ir2_decode_plane_inter(Ir2Context *ctx, int width, int height, uint8_t *dst,

117 int pitch, const uint8_t *table)

118 {

119 int j;

120 int out = 0;

121 int c;

122 int t;

123

124 if (width & 1)

125 return AVERROR_INVALIDDATA;

126

127 for (j = 0; j < height; j++) {

128 out = 0;

129 while (out < width) {

130 if (get_bits_left(&ctx->gb) <= 0)

131 return AVERROR_INVALIDDATA;

132 c = ir2_get_code(&ctx->gb);

133 if (c >= 0x80) { /* we have a skip */

134 c -= 0x7F;

135 out += c * 2;

136 } else { /* add two deltas from table */

137 if (c <= 0)

138 return AVERROR_INVALIDDATA;

139 t = dst[out] + (((table[c * 2] - 128)*3) >> 2);

140 t = av_clip_uint8(t);

141 dst[out] = t;

142 out++;

143 t = dst[out] + (((table[(c * 2) + 1] - 128)*3) >> 2);

144 t = av_clip_uint8(t);

145 dst[out] = t;

146 out++;

147 }

148 }

149 dst += pitch;

150 }

151 return 0;

152 }

153

154 static int ir2_decode_frame(AVCodecContext *avctx, AVFrame *picture,

155 int *got_frame, AVPacket *avpkt)

156 {

157 Ir2Context * const s = avctx->priv_data;

158 const uint8_t *buf = avpkt->data;

159 int buf_size = avpkt->size;

160 AVFrame * const p = s->picture;

161 int start, ret;

162 int ltab, ctab;

163

164 if ((ret = ff_reget_buffer(avctx, p, 0)) < 0)

165 return ret;

166

167 start = 48; /* hardcoded for now */

168

169 if (start >= buf_size) {

170 av_log(s->avctx, AV_LOG_ERROR, "input buffer size too small (%d)\n", buf_size);

171 return AVERROR_INVALIDDATA;

172 }

173

174 s->decode_delta = buf[18];

175

176 /* decide whether frame uses deltas or not */

177

178 if ((ret = init_get_bits8(&s->gb, buf + start, buf_size - start)) < 0)

179 return ret;

180

181 ltab = buf[0x22] & 3;

182 ctab = buf[0x22] >> 2;

183

184 if (ctab > 3) {

185 av_log(avctx, AV_LOG_ERROR, "ctab %d is invalid\n", ctab);

186 return AVERROR_INVALIDDATA;

187 }

188

189 if (s->decode_delta) { /* intraframe */

190 if ((ret = ir2_decode_plane(s, avctx->width, avctx->height,

191 p->data[0], p->linesize[0],

192 ir2_delta_table[ltab])) < 0)

193 return ret;

194

195 /* swapped U and V */

196 if ((ret = ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,

197 p->data[2], p->linesize[2],

198 ir2_delta_table[ctab])) < 0)

199 return ret;

200 if ((ret = ir2_decode_plane(s, avctx->width >> 2, avctx->height >> 2,

201 p->data[1], p->linesize[1],

202 ir2_delta_table[ctab])) < 0)

203 return ret;

204 } else { /* interframe */

205 if ((ret = ir2_decode_plane_inter(s, avctx->width, avctx->height,

206 p->data[0], p->linesize[0],

207 ir2_delta_table[ltab])) < 0)

208 return ret;

209 /* swapped U and V */

210 if ((ret = ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,

211 p->data[2], p->linesize[2],

212 ir2_delta_table[ctab])) < 0)

213 return ret;

214 if ((ret = ir2_decode_plane_inter(s, avctx->width >> 2, avctx->height >> 2,

215 p->data[1], p->linesize[1],

216 ir2_delta_table[ctab])) < 0)

217 return ret;

218 }

219

220 if ((ret = av_frame_ref(picture, p)) < 0)

221 return ret;

222

223 *got_frame = 1;

224

225 return buf_size;

226 }

227

228 static av_cold void ir2_init_static(void)

229 {

230 INIT_VLC_STATIC_FROM_LENGTHS(&ir2_vlc, CODE_VLC_BITS, IR2_CODES,

231 &ir2_tab[0][1], 2, &ir2_tab[0][0], 2, 1,

232 0, INIT_VLC_OUTPUT_LE, 1 << CODE_VLC_BITS);

233 }

234

235 static av_cold int ir2_decode_init(AVCodecContext *avctx)

236 {

237 static AVOnce init_static_once = AV_ONCE_INIT;

238 Ir2Context * const ic = avctx->priv_data;

239

240 ic->avctx = avctx;

241

242 avctx->pix_fmt= AV_PIX_FMT_YUV410P;

243

244 ic->picture = av_frame_alloc();

245 if (!ic->picture)

246 return AVERROR(ENOMEM);

247

248 ff_thread_once(&init_static_once, ir2_init_static);

249

250 return 0;

251 }

252

253 static av_cold int ir2_decode_end(AVCodecContext *avctx)

254 {

255 Ir2Context * const ic = avctx->priv_data;

256

257 av_frame_free(&ic->picture);

258

259 return 0;

260 }

261

262 const FFCodec ff_indeo2_decoder = {

263 .p.name = "indeo2",

264 .p.long_name = NULL_IF_CONFIG_SMALL("Intel Indeo 2"),

265 .p.type = AVMEDIA_TYPE_VIDEO,

266 .p.id = AV_CODEC_ID_INDEO2,

267 .priv_data_size = sizeof(Ir2Context),

268 .init = ir2_decode_init,

269 .close = ir2_decode_end,

270 FF_CODEC_DECODE_CB(ir2_decode_frame),

271 .p.capabilities = AV_CODEC_CAP_DR1,

272 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,

273 };

IR2_CODES

#define IR2_CODES

Definition: indeo2data.h:27

get_bits_left

static int get_bits_left(GetBitContext *gb)

Definition: get_bits.h:839

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

ir2_decode_plane_inter

static int ir2_decode_plane_inter(Ir2Context *ctx, int width, int height, uint8_t *dst, int pitch, const uint8_t *table)

Definition: indeo2.c:116

out

FILE * out

Definition: movenc.c:54

INIT_VLC_OUTPUT_LE

#define INIT_VLC_OUTPUT_LE

Definition: vlc.h:98

thread.h

indeo2data.h

av_frame_free

void av_frame_free(AVFrame **frame)

Free the frame and any dynamically allocated objects in it, e.g.

Definition: frame.c:111

ir2_vlc

static VLC ir2_vlc

Definition: indeo2.c:46

AVFrame

This structure describes decoded (raw) audio or video data.

Definition: frame.h:325

ir2_delta_table

static const uint8_t ir2_delta_table[4][256]

Definition: indeo2data.h:60

internal.h

AVPacket::data

uint8_t * data

Definition: packet.h:374

table

static const uint16_t table[]

Definition: prosumer.c:206

Ir2Context::gb

GetBitContext gb

Definition: indeo2.c:41

ir2_decode_frame

static int ir2_decode_frame(AVCodecContext *avctx, AVFrame *picture, int *got_frame, AVPacket *avpkt)

Definition: indeo2.c:154

FFCodec

Definition: codec_internal.h:112

AVFrame::data

uint8_t * data[AV_NUM_DATA_POINTERS]

pointer to the picture/channel planes.

Definition: frame.h:346

init

static int init

Definition: av_tx.c:47

ir2_decode_end

static av_cold int ir2_decode_end(AVCodecContext *avctx)

Definition: indeo2.c:253

FFCodec::p

AVCodec p

The public AVCodec.

Definition: codec_internal.h:116

GetBitContext

Definition: get_bits.h:61

av_frame_alloc

AVFrame * av_frame_alloc(void)

Allocate an AVFrame and set its fields to default values.

Definition: frame.c:99

ir2_tab

static const uint8_t ir2_tab[IR2_CODES][2]

Definition: indeo2data.h:28

ff_thread_once

static int ff_thread_once(char *control, void(*routine)(void))

Definition: thread.h:179

AV_LOG_ERROR

#define AV_LOG_ERROR

Something went wrong and cannot losslessly be recovered.

Definition: log.h:180

av_cold

#define av_cold

Definition: attributes.h:90

init_get_bits8

static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)

Initialize GetBitContext.

Definition: get_bits.h:667

width

#define width

FF_CODEC_DECODE_CB

#define FF_CODEC_DECODE_CB(func)

Definition: codec_internal.h:254

#define s(width, name)

Definition: cbs_vp9.c:256

ff_indeo2_decoder

const FFCodec ff_indeo2_decoder

Definition: indeo2.c:262

ctx

AVFormatContext * ctx

Definition: movenc.c:48

get_bits.h

ir2_get_code

static int ir2_get_code(GetBitContext *gb)

Definition: indeo2.c:49

AV_ONCE_INIT

#define AV_ONCE_INIT

Definition: thread.h:177

INIT_VLC_STATIC_FROM_LENGTHS

#define INIT_VLC_STATIC_FROM_LENGTHS(vlc, bits, nb_codes, lens, len_wrap, symbols, symbols_wrap, symbols_size, offset, flags, static_size)

Definition: vlc.h:131

mathops.h

get_vlc2

static av_always_inline int get_vlc2(GetBitContext *s, const VLCElem *table, int bits, int max_depth)

Parse a vlc code.

Definition: get_bits.h:787

ir2_init_static

static av_cold void ir2_init_static(void)

Definition: indeo2.c:228

AVOnce

#define AVOnce

Definition: thread.h:176

Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c

Definition: undefined.txt:32

AV_CODEC_ID_INDEO2

@ AV_CODEC_ID_INDEO2

Definition: codec_id.h:125

AV_CODEC_CAP_DR1

#define AV_CODEC_CAP_DR1

Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.

Definition: codec.h:52

AVPacket::size

int size

Definition: packet.h:375

NULL_IF_CONFIG_SMALL