FFmpeg: libavcodec/targa.c Source File

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libavcodec

targa.c

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1 /*

2 * Targa (.tga) image decoder

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/intreadwrite.h"

23 #include "libavutil/imgutils.h"

24 #include "avcodec.h"

25 #include "bytestream.h"

26 #include "internal.h"

27 #include "targa.h"

29 typedef struct TargaContext {

30 GetByteContext gb;

31 } TargaContext;

33 static uint8_t *advance_line(uint8_t *start, uint8_t *line,

34 int stride, int *y, int h, int interleave)

35 {

36 *y += interleave;

38 if (*y < h) {

39 return line + interleave * stride;

40 } else {

41 *y = (*y + 1) & (interleave - 1);

42 if (*y && *y < h) {

43 return start + *y * stride;

44 } else {

45 return NULL;

46 }

47 }

48 }

50 static int targa_decode_rle(AVCodecContext *avctx, TargaContext *s,

51 uint8_t *start, int w, int h, int stride,

52 int bpp, int interleave)

53 {

54 int x, y;

55 int depth = (bpp + 1) >> 3;

56 int type, count;

57 uint8_t *line = start;

58 uint8_t *dst = line;

60 x = y = count = 0;

61 while (dst) {

62 if (bytestream2_get_bytes_left(&s->gb) <= 0) {

63 av_log(avctx, AV_LOG_ERROR,

64 "Ran ouf of data before end-of-image\n");

65 return AVERROR_INVALIDDATA;

66 }

67 type = bytestream2_get_byteu(&s->gb);

68 count = (type & 0x7F) + 1;

69 type &= 0x80;

70 if (!type) {

71 do {

72 int n = FFMIN(count, w - x);

73 bytestream2_get_buffer(&s->gb, dst, n * depth);

74 count -= n;

75 dst += n * depth;

76 x += n;

77 if (x == w) {

78 x = 0;

79 dst = line = advance_line(start, line, stride, &y, h, interleave);

80 }

81 } while (dst && count > 0);

82 } else {

83 uint8_t tmp[4];

84 bytestream2_get_buffer(&s->gb, tmp, depth);

85 do {

86 int n = FFMIN(count, w - x);

87 count -= n;

88 x += n;

89 do {

90 memcpy(dst, tmp, depth);

91 dst += depth;

92 } while (--n);

93 if (x == w) {

94 x = 0;

95 dst = line = advance_line(start, line, stride, &y, h, interleave);

96 }

97 } while (dst && count > 0);

98 }

99 }

100

101 if (count) {

102 av_log(avctx, AV_LOG_ERROR, "Packet went out of bounds\n");

103 return AVERROR_INVALIDDATA;

104 }

105

106 return 0;

107 }

108

109 static int decode_frame(AVCodecContext *avctx,

110 void *data, int *got_frame,

111 AVPacket *avpkt)

112 {

113 TargaContext * const s = avctx->priv_data;

114 AVFrame * const p = data;

115 uint8_t *dst;

116 int stride;

117 int idlen, pal, compr, y, w, h, bpp, flags, ret;

118 int first_clr, colors, csize;

119 int interleave;

120

121 bytestream2_init(&s->gb, avpkt->data, avpkt->size);

122

123 /* parse image header */

124 idlen = bytestream2_get_byte(&s->gb);

125 pal = bytestream2_get_byte(&s->gb);

126 compr = bytestream2_get_byte(&s->gb);

127 first_clr = bytestream2_get_le16(&s->gb);

128 colors = bytestream2_get_le16(&s->gb);

129 csize = bytestream2_get_byte(&s->gb);

130 bytestream2_skip(&s->gb, 4); /* 2: x, 2: y */

131 w = bytestream2_get_le16(&s->gb);

132 h = bytestream2_get_le16(&s->gb);

133 bpp = bytestream2_get_byte(&s->gb);

134

135 if (bytestream2_get_bytes_left(&s->gb) <= idlen) {

136 av_log(avctx, AV_LOG_ERROR,

137 "Not enough data to read header\n");

138 return AVERROR_INVALIDDATA;

139 }

140

141 flags = bytestream2_get_byte(&s->gb);

142

143 if (!pal && (first_clr || colors || csize)) {

144 av_log(avctx, AV_LOG_WARNING, "File without colormap has colormap information set.\n");

145 // specification says we should ignore those value in this case

146 first_clr = colors = csize = 0;

147 }

148

149 // skip identifier if any

150 bytestream2_skip(&s->gb, idlen);

151

152 switch (bpp) {

153 case 8:

154 avctx->pix_fmt = ((compr & (~TGA_RLE)) == TGA_BW) ? AV_PIX_FMT_GRAY8 : AV_PIX_FMT_PAL8;

155 break;

156 case 15:

157 case 16:

158 avctx->pix_fmt = AV_PIX_FMT_RGB555LE;

159 break;

160 case 24:

161 avctx->pix_fmt = AV_PIX_FMT_BGR24;

162 break;

163 case 32:

164 avctx->pix_fmt = AV_PIX_FMT_BGRA;

165 break;

166 default:

167 av_log(avctx, AV_LOG_ERROR, "Bit depth %i is not supported\n", bpp);

168 return AVERROR_INVALIDDATA;

169 }

170

171 if (colors && (colors + first_clr) > 256) {

172 av_log(avctx, AV_LOG_ERROR, "Incorrect palette: %i colors with offset %i\n", colors, first_clr);

173 return AVERROR_INVALIDDATA;

174 }

175

176 if ((ret = av_image_check_size(w, h, 0, avctx)) < 0)

177 return ret;

178 if (w != avctx->width || h != avctx->height)

179 avcodec_set_dimensions(avctx, w, h);

180 if ((ret = ff_get_buffer(avctx, p, 0)) < 0)

181 return ret;

182 p->pict_type = AV_PICTURE_TYPE_I;

183

184 if (flags & TGA_TOPTOBOTTOM) {

185 dst = p->data[0];

186 stride = p->linesize[0];

187 } else { //image is upside-down

188 dst = p->data[0] + p->linesize[0] * (h - 1);

189 stride = -p->linesize[0];

190 }

191

192 interleave = flags & TGA_INTERLEAVE2 ? 2 :

193 flags & TGA_INTERLEAVE4 ? 4 : 1;

194

195 if (colors) {

196 int pal_size, pal_sample_size;

197

198 switch (csize) {

199 case 32: pal_sample_size = 4; break;

200 case 24: pal_sample_size = 3; break;

201 case 16:

202 case 15: pal_sample_size = 2; break;

203 default:

204 av_log(avctx, AV_LOG_ERROR, "Palette entry size %i bits is not supported\n", csize);

205 return AVERROR_INVALIDDATA;

206 }

207 pal_size = colors * pal_sample_size;

208 if (avctx->pix_fmt != AV_PIX_FMT_PAL8) //should not occur but skip palette anyway

209 bytestream2_skip(&s->gb, pal_size);

210 else {

211 int t;

212 uint32_t *pal = ((uint32_t *)p->data[1]) + first_clr;

213

214 if (bytestream2_get_bytes_left(&s->gb) < pal_size) {

215 av_log(avctx, AV_LOG_ERROR,

216 "Not enough data to read palette\n");

217 return AVERROR_INVALIDDATA;

218 }

219 switch (pal_sample_size) {

220 case 4:

221 for (t = 0; t < colors; t++)

222 *pal++ = bytestream2_get_le32u(&s->gb);

223 break;

224 case 3:

225 /* RGB24 */

226 for (t = 0; t < colors; t++)

227 *pal++ = (0xffU<<24) | bytestream2_get_le24u(&s->gb);

228 break;

229 case 2:

230 /* RGB555 */

231 for (t = 0; t < colors; t++) {

232 uint32_t v = bytestream2_get_le16u(&s->gb);

233 v = ((v & 0x7C00) << 9) |

234 ((v & 0x03E0) << 6) |

235 ((v & 0x001F) << 3);

236 /* left bit replication */

237 v |= (v & 0xE0E0E0U) >> 5;

238 *pal++ = (0xffU<<24) | v;

239 }

240 break;

241 }

242 p->palette_has_changed = 1;

243 }

244 }

245

246 if ((compr & (~TGA_RLE)) == TGA_NODATA) {

247 memset(p->data[0], 0, p->linesize[0] * h);

248 } else {

249 if (compr & TGA_RLE) {

250 int res = targa_decode_rle(avctx, s, dst, w, h, stride, bpp, interleave);

251 if (res < 0)

252 return res;

253 } else {

254 size_t img_size = w * ((bpp + 1) >> 3);

255 uint8_t *line;

256 if (bytestream2_get_bytes_left(&s->gb) < img_size * h) {

257 av_log(avctx, AV_LOG_ERROR,

258 "Not enough data available for image\n");

259 return AVERROR_INVALIDDATA;

260 }

261

262 line = dst;

263 y = 0;

264 do {

265 bytestream2_get_buffer(&s->gb, line, img_size);

266 line = advance_line(dst, line, stride, &y, h, interleave);

267 } while (line);

268 }

269 }

270

271 if (flags & TGA_RIGHTTOLEFT) { // right-to-left, needs horizontal flip

272 int x;

273 for (y = 0; y < h; y++) {

274 void *line = &p->data[0][y * p->linesize[0]];

275 for (x = 0; x < w >> 1; x++) {

276 switch (bpp) {

277 case 32:

278 FFSWAP(uint32_t, ((uint32_t *)line)[x], ((uint32_t *)line)[w - x - 1]);

279 break;

280 case 24:

281 FFSWAP(uint8_t, ((uint8_t *)line)[3 * x ], ((uint8_t *)line)[3 * w - 3 * x - 3]);

282 FFSWAP(uint8_t, ((uint8_t *)line)[3 * x + 1], ((uint8_t *)line)[3 * w - 3 * x - 2]);

283 FFSWAP(uint8_t, ((uint8_t *)line)[3 * x + 2], ((uint8_t *)line)[3 * w - 3 * x - 1]);

284 break;

285 case 16:

286 FFSWAP(uint16_t, ((uint16_t *)line)[x], ((uint16_t *)line)[w - x - 1]);

287 break;

288 case 8:

289 FFSWAP(uint8_t, ((uint8_t *)line)[x], ((uint8_t *)line)[w - x - 1]);

290 }

291 }

292 }

293 }

294

295 *got_frame = 1;

296

297 return avpkt->size;

298 }

299

300 AVCodec ff_targa_decoder = {

301 .name = "targa",

302 .long_name = NULL_IF_CONFIG_SMALL("Truevision Targa image"),

303 .type = AVMEDIA_TYPE_VIDEO,

304 .id = AV_CODEC_ID_TARGA,

305 .priv_data_size = sizeof(TargaContext),

306 .decode = decode_frame,

307 .capabilities = CODEC_CAP_DR1,

308 };

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