FFmpeg: libavcodec/sp5xdec.c Source File

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libavcodec

sp5xdec.c

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1 /*

2 * Sunplus JPEG decoder (SP5X)

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 * Sunplus JPEG decoder (SP5X).

25 */

27 #include "avcodec.h"

28 #include "mjpeg.h"

29 #include "mjpegdec.h"

30 #include "sp5x.h"

33 static int sp5x_decode_frame(AVCodecContext *avctx,

34 void *data, int *got_frame,

35 AVPacket *avpkt)

36 {

37 const uint8_t *buf = avpkt->data;

38 int buf_size = avpkt->size;

39 AVPacket avpkt_recoded;

40 const int qscale = 5;

41 uint8_t *recoded;

42 int i = 0, j = 0;

44 if (!avctx->width || !avctx->height)

45 return -1;

47 recoded = av_mallocz(buf_size + 1024);

48 if (!recoded)

49 return -1;

51 /* SOI */

52 recoded[j++] = 0xFF;

53 recoded[j++] = 0xD8;

55 memcpy(recoded+j, &sp5x_data_dqt[0], sizeof(sp5x_data_dqt));

56 memcpy(recoded+j+5, &sp5x_quant_table[qscale * 2], 64);

57 memcpy(recoded+j+70, &sp5x_quant_table[(qscale * 2) + 1], 64);

58 j += sizeof(sp5x_data_dqt);

60 memcpy(recoded+j, &sp5x_data_dht[0], sizeof(sp5x_data_dht));

61 j += sizeof(sp5x_data_dht);

63 memcpy(recoded+j, &sp5x_data_sof[0], sizeof(sp5x_data_sof));

64 AV_WB16(recoded+j+5, avctx->coded_height);

65 AV_WB16(recoded+j+7, avctx->coded_width);

66 j += sizeof(sp5x_data_sof);

68 memcpy(recoded+j, &sp5x_data_sos[0], sizeof(sp5x_data_sos));

69 j += sizeof(sp5x_data_sos);

71 if(avctx->codec_id==AV_CODEC_ID_AMV)

72 for (i = 2; i < buf_size-2 && j < buf_size+1024-2; i++)

73 recoded[j++] = buf[i];

74 else

75 for (i = 14; i < buf_size && j < buf_size+1024-3; i++)

76 {

77 recoded[j++] = buf[i];

78 if (buf[i] == 0xff)

79 recoded[j++] = 0;

80 }

82 /* EOI */

83 recoded[j++] = 0xFF;

84 recoded[j++] = 0xD9;

86 av_init_packet(&avpkt_recoded);

87 avpkt_recoded.data = recoded;

88 avpkt_recoded.size = j;

89 i = ff_mjpeg_decode_frame(avctx, data, got_frame, &avpkt_recoded);

91 av_free(recoded);

93 return i < 0 ? i : avpkt->size;

94 }

96 #if CONFIG_SP5X_DECODER

97 AVCodec ff_sp5x_decoder = {

98 .name = "sp5x",

99 .long_name = NULL_IF_CONFIG_SMALL("Sunplus JPEG (SP5X)"),

100 .type = AVMEDIA_TYPE_VIDEO,

101 .id = AV_CODEC_ID_SP5X,

102 .priv_data_size = sizeof(MJpegDecodeContext),

103 .init = ff_mjpeg_decode_init,

104 .close = ff_mjpeg_decode_end,

105 .decode = sp5x_decode_frame,

106 .capabilities = CODEC_CAP_DR1,

107 .max_lowres = 3,

108 };

109 #endif

110 #if CONFIG_AMV_DECODER

111 AVCodec ff_amv_decoder = {

112 .name = "amv",

113 .long_name = NULL_IF_CONFIG_SMALL("AMV Video"),

114 .type = AVMEDIA_TYPE_VIDEO,

115 .id = AV_CODEC_ID_AMV,

116 .priv_data_size = sizeof(MJpegDecodeContext),

117 .init = ff_mjpeg_decode_init,

118 .close = ff_mjpeg_decode_end,

119 .decode = sp5x_decode_frame,

120 };

121 #endif

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