FFmpeg: libavcodec/anm.c Source File

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libavcodec

anm.c

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1 /*

2 * Deluxe Paint Animation 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 /**

23 * @file

24 * Deluxe Paint Animation decoder

25 */

27 #include "avcodec.h"

28 #include "bytestream.h"

29 #include "internal.h"

31 typedef struct AnmContext {

32 AVFrame *frame;

33 int palette[AVPALETTE_COUNT];

34 GetByteContext gb;

35 int x; ///< x coordinate position

36 } AnmContext;

38 static av_cold int decode_init(AVCodecContext *avctx)

39 {

40 AnmContext *s = avctx->priv_data;

41 int i;

43 avctx->pix_fmt = AV_PIX_FMT_PAL8;

45 s->frame = av_frame_alloc();

46 if (!s->frame)

47 return AVERROR(ENOMEM);

49 bytestream2_init(&s->gb, avctx->extradata, avctx->extradata_size);

50 if (bytestream2_get_bytes_left(&s->gb) < 16 * 8 + 4 * 256)

51 return AVERROR_INVALIDDATA;

53 bytestream2_skipu(&s->gb, 16 * 8);

54 for (i = 0; i < 256; i++)

55 s->palette[i] = bytestream2_get_le32u(&s->gb);

57 return 0;

58 }

60 /**

61 * Perform decode operation

62 * @param dst pointer to destination image buffer

63 * @param dst_end pointer to end of destination image buffer

64 * @param gb GetByteContext (optional, see below)

65 * @param pixel Fill color (optional, see below)

66 * @param count Pixel count

67 * @param x Pointer to x-axis counter

68 * @param width Image width

69 * @param linesize Destination image buffer linesize

70 * @return non-zero if destination buffer is exhausted

71 *

72 * a copy operation is achieved when 'gb' is set

73 * a fill operation is achieved when 'gb' is null and pixel is >= 0

74 * a skip operation is achieved when 'gb' is null and pixel is < 0

75 */

76 static inline int op(uint8_t **dst, const uint8_t *dst_end,

77 GetByteContext *gb,

78 int pixel, int count,

79 int *x, int width, int linesize)

80 {

81 int remaining = width - *x;

82 while(count > 0) {

83 int striplen = FFMIN(count, remaining);

84 if (gb) {

85 if (bytestream2_get_bytes_left(gb) < striplen)

86 goto exhausted;

87 bytestream2_get_bufferu(gb, *dst, striplen);

88 } else if (pixel >= 0)

89 memset(*dst, pixel, striplen);

90 *dst += striplen;

91 remaining -= striplen;

92 count -= striplen;

93 if (remaining <= 0) {

94 *dst += linesize - width;

95 remaining = width;

96 }

97 if (linesize > 0) {

98 if (*dst >= dst_end) goto exhausted;

99 } else {

100 if (*dst <= dst_end) goto exhausted;

101 }

102 }

103 *x = width - remaining;

104 return 0;

105

106 exhausted:

107 *x = width - remaining;

108 return 1;

109 }

110

111 static int decode_frame(AVCodecContext *avctx,

112 void *data, int *got_frame,

113 AVPacket *avpkt)

114 {

115 AnmContext *s = avctx->priv_data;

116 const int buf_size = avpkt->size;

117 uint8_t *dst, *dst_end;

118 int count, ret;

119

120 if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)

121 return ret;

122 dst = s->frame->data[0];

123 dst_end = s->frame->data[0] + s->frame->linesize[0]*avctx->height;

124

125 bytestream2_init(&s->gb, avpkt->data, buf_size);

126

127 if (bytestream2_get_byte(&s->gb) != 0x42) {

128 avpriv_request_sample(avctx, "Unknown record type");

129 return AVERROR_INVALIDDATA;

130 }

131 if (bytestream2_get_byte(&s->gb)) {

132 avpriv_request_sample(avctx, "Padding bytes");

133 return AVERROR_PATCHWELCOME;

134 }

135 bytestream2_skip(&s->gb, 2);

136

137 s->x = 0;

138 do {

139 /* if statements are ordered by probability */

140 #define OP(gb, pixel, count) \

141 op(&dst, dst_end, (gb), (pixel), (count), &s->x, avctx->width, s->frame->linesize[0])

142

143 int type = bytestream2_get_byte(&s->gb);

144 count = type & 0x7F;

145 type >>= 7;

146 if (count) {

147 if (OP(type ? NULL : &s->gb, -1, count)) break;

148 } else if (!type) {

149 int pixel;

150 count = bytestream2_get_byte(&s->gb); /* count==0 gives nop */

151 pixel = bytestream2_get_byte(&s->gb);

152 if (OP(NULL, pixel, count)) break;

153 } else {

154 int pixel;

155 type = bytestream2_get_le16(&s->gb);

156 count = type & 0x3FFF;

157 type >>= 14;

158 if (!count) {

159 if (type == 0)

160 break; // stop

161 if (type == 2) {

162 avpriv_request_sample(avctx, "Unknown opcode");

163 return AVERROR_PATCHWELCOME;

164 }

165 continue;

166 }

167 pixel = type == 3 ? bytestream2_get_byte(&s->gb) : -1;

168 if (type == 1) count += 0x4000;

169 if (OP(type == 2 ? &s->gb : NULL, pixel, count)) break;

170 }

171 } while (bytestream2_get_bytes_left(&s->gb) > 0);

172

173 memcpy(s->frame->data[1], s->palette, AVPALETTE_SIZE);

174

175 *got_frame = 1;

176 if ((ret = av_frame_ref(data, s->frame)) < 0)

177 return ret;

178

179 return buf_size;

180 }

181

182 static av_cold int decode_end(AVCodecContext *avctx)

183 {

184 AnmContext *s = avctx->priv_data;

185

186 av_frame_free(&s->frame);

187 return 0;

188 }

189

190 AVCodec ff_anm_decoder = {

191 .name = "anm",

192 .long_name = NULL_IF_CONFIG_SMALL("Deluxe Paint Animation"),

193 .type = AVMEDIA_TYPE_VIDEO,

194 .id = AV_CODEC_ID_ANM,

195 .priv_data_size = sizeof(AnmContext),

196 .init = decode_init,

197 .close = decode_end,

198 .decode = decode_frame,

199 .capabilities = CODEC_CAP_DR1,

200 };

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