FFmpeg: libavformat/frmdec.c Source File

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libavformat

frmdec.c

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1 /*

2 * Megalux Frame demuxer

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 * Megalux Frame demuxer

25 */

27 #include "libavcodec/raw.h"

28 #include "libavutil/intreadwrite.h"

29 #include "avformat.h"

31 static const PixelFormatTag frm_pix_fmt_tags[] = {

32 { AV_PIX_FMT_RGB555, 1 },

33 { AV_PIX_FMT_RGB0, 2 },

34 { AV_PIX_FMT_RGB24, 3 },

35 { AV_PIX_FMT_BGR0, 4 },

36 { AV_PIX_FMT_BGRA, 5 },

37 { AV_PIX_FMT_NONE, 0 },

38 };

40 typedef struct {

41 int count;

42 } FrmContext;

44 static int frm_read_probe(AVProbeData *p)

45 {

46 if (p->buf_size > 8 &&

47 p->buf[0] == 'F' && p->buf[1] == 'R' && p->buf[2] == 'M' &&

48 AV_RL16(&p->buf[4]) && AV_RL16(&p->buf[6]))

49 return AVPROBE_SCORE_MAX / 4;

50 return 0;

51 }

53 static int frm_read_header(AVFormatContext *avctx)

54 {

55 AVIOContext *pb = avctx->pb;

56 AVStream *st = avformat_new_stream(avctx, 0);

57 if (!st)

58 return AVERROR(ENOMEM);

60 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

61 st->codec->codec_id = AV_CODEC_ID_RAWVIDEO;

62 avio_skip(pb, 3);

64 st->codec->pix_fmt = avpriv_find_pix_fmt(frm_pix_fmt_tags, avio_r8(pb));

65 if (!st->codec->pix_fmt)

66 return AVERROR_INVALIDDATA;

68 st->codec->codec_tag = 0;

69 st->codec->width = avio_rl16(pb);

70 st->codec->height = avio_rl16(pb);

71 return 0;

72 }

74 static int frm_read_packet(AVFormatContext *avctx, AVPacket *pkt)

75 {

76 FrmContext *s = avctx->priv_data;

77 AVCodecContext *stc = avctx->streams[0]->codec;

78 int packet_size, ret;

80 if (s->count)

81 return AVERROR_EOF;

83 packet_size = avpicture_get_size(stc->pix_fmt, stc->width, stc->height);

84 if (packet_size < 0)

85 return AVERROR_INVALIDDATA;

87 ret = av_get_packet(avctx->pb, pkt, packet_size);

88 if (ret < 0)

89 return ret;

91 if (stc->pix_fmt == AV_PIX_FMT_BGRA) {

92 int i;

93 for (i = 3; i + 1 <= pkt->size; i += 4)

94 pkt->data[i] = 0xFF - pkt->data[i];

95 }

97 pkt->stream_index = 0;

98 s->count++;

100 return 0;

101 }

102

103 AVInputFormat ff_frm_demuxer = {

104 .name = "frm",

105 .priv_data_size = sizeof(FrmContext),

106 .long_name = NULL_IF_CONFIG_SMALL("Megalux Frame"),

107 .read_probe = frm_read_probe,

108 .read_header = frm_read_header,

109 .read_packet = frm_read_packet,

110 };

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