FFmpeg: libavcodec/avrndec.c Source File

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libavcodec

avrndec.c

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1 /*

2 * AVRn 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 "avcodec.h"

23 #include "internal.h"

24 #include "mjpeg.h"

25 #include "mjpegdec.h"

26 #include "libavutil/imgutils.h"

28 typedef struct {

29 MJpegDecodeContext mjpeg_ctx;

30 int is_mjpeg;

31 int interlace; //FIXME use frame.interlaced_frame

32 int tff;

33 } AVRnContext;

35 static av_cold int init(AVCodecContext *avctx)

36 {

37 AVRnContext *a = avctx->priv_data;

38 int ret;

40 // Support "Resolution 1:1" for Avid AVI Codec

41 a->is_mjpeg = avctx->extradata_size < 31 || memcmp(&avctx->extradata[28], "1:1", 3);

43 if(!a->is_mjpeg && avctx->lowres) {

44 av_log(avctx, AV_LOG_ERROR, "lowres is not possible with rawvideo\n");

45 return AVERROR(EINVAL);

46 }

48 if(a->is_mjpeg)

49 return ff_mjpeg_decode_init(avctx);

51 if ((ret = av_image_check_size(avctx->width, avctx->height, 0, avctx)) < 0)

52 return ret;

54 avctx->pix_fmt = AV_PIX_FMT_UYVY422;

56 if(avctx->extradata_size >= 9 && avctx->extradata[4]+28 < avctx->extradata_size) {

57 int ndx = avctx->extradata[4] + 4;

58 a->interlace = !memcmp(avctx->extradata + ndx, "1:1(", 4);

59 if(a->interlace) {

60 a->tff = avctx->extradata[ndx + 24] == 1;

61 }

62 }

64 return 0;

65 }

67 static av_cold int end(AVCodecContext *avctx)

68 {

69 AVRnContext *a = avctx->priv_data;

71 if(a->is_mjpeg)

72 ff_mjpeg_decode_end(avctx);

74 return 0;

75 }

77 static int decode_frame(AVCodecContext *avctx, void *data,

78 int *got_frame, AVPacket *avpkt)

79 {

80 AVRnContext *a = avctx->priv_data;

81 AVFrame *p = data;

82 const uint8_t *buf = avpkt->data;

83 int buf_size = avpkt->size;

84 int y, ret, true_height;

86 if(a->is_mjpeg)

87 return ff_mjpeg_decode_frame(avctx, data, got_frame, avpkt);

89 true_height = buf_size / (2*avctx->width);

91 if(buf_size < 2*avctx->width * avctx->height) {

92 av_log(avctx, AV_LOG_ERROR, "packet too small\n");

93 return AVERROR_INVALIDDATA;

94 }

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

97 return ret;

98 p->pict_type= AV_PICTURE_TYPE_I;

99 p->key_frame= 1;

100

101 if(a->interlace) {

102 buf += (true_height - avctx->height)*avctx->width;

103 for(y = 0; y < avctx->height-1; y+=2) {

104 memcpy(p->data[0] + (y+ a->tff)*p->linesize[0], buf , 2*avctx->width);

105 memcpy(p->data[0] + (y+!a->tff)*p->linesize[0], buf + avctx->width*true_height+4, 2*avctx->width);

106 buf += 2*avctx->width;

107 }

108 } else {

109 buf += (true_height - avctx->height)*avctx->width*2;

110 for(y = 0; y < avctx->height; y++) {

111 memcpy(p->data[0] + y*p->linesize[0], buf, 2*avctx->width);

112 buf += 2*avctx->width;

113 }

114 }

115

116 *got_frame = 1;

117 return buf_size;

118 }

119

120 AVCodec ff_avrn_decoder = {

121 .name = "avrn",

122 .type = AVMEDIA_TYPE_VIDEO,

123 .id = AV_CODEC_ID_AVRN,

124 .priv_data_size = sizeof(AVRnContext),

125 .init = init,

126 .close = end,

127 .decode = decode_frame,

128 .long_name = NULL_IF_CONFIG_SMALL("Avid AVI Codec"),

129 .capabilities = CODEC_CAP_DR1,

130 .max_lowres = 3,

131 };

132

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