Statistics
| Branch: | Revision:

ffmpeg / libavcodec / pnm_parser.c @ 2912e87a

History | View | Annotate | Download (2.92 KB)

1
/*
2
 * PNM image parser
3
 * Copyright (c) 2002, 2003 Fabrice Bellard
4
 *
5
 * This file is part of Libav.
6
 *
7
 * Libav 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
 * Libav 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 Libav; if not, write to the Free Software
19
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20
 */
21

    
22
#include "parser.h" //for ParseContext
23
#include "pnm.h"
24

    
25

    
26
static int pnm_parse(AVCodecParserContext *s, AVCodecContext *avctx,
27
                     const uint8_t **poutbuf, int *poutbuf_size,
28
                     const uint8_t *buf, int buf_size)
29
{
30
    ParseContext *pc = s->priv_data;
31
    PNMContext pnmctx;
32
    int next;
33

    
34
    for (; pc->overread > 0; pc->overread--) {
35
        pc->buffer[pc->index++]= pc->buffer[pc->overread_index++];
36
    }
37
retry:
38
    if (pc->index) {
39
        pnmctx.bytestream_start =
40
        pnmctx.bytestream       = pc->buffer;
41
        pnmctx.bytestream_end   = pc->buffer + pc->index;
42
    } else {
43
        pnmctx.bytestream_start =
44
        pnmctx.bytestream       = (uint8_t *) buf; /* casts avoid warnings */
45
        pnmctx.bytestream_end   = (uint8_t *) buf + buf_size;
46
    }
47
    if (ff_pnm_decode_header(avctx, &pnmctx) < 0) {
48
        if (pnmctx.bytestream < pnmctx.bytestream_end) {
49
            if (pc->index) {
50
                pc->index = 0;
51
            } else {
52
                buf++;
53
                buf_size--;
54
            }
55
            goto retry;
56
        }
57
#if 0
58
        if (pc->index && pc->index * 2 + FF_INPUT_BUFFER_PADDING_SIZE < pc->buffer_size && buf_size > pc->index) {
59
            memcpy(pc->buffer + pc->index, buf, pc->index);
60
            pc->index += pc->index;
61
            buf       += pc->index;
62
            buf_size  -= pc->index;
63
            goto retry;
64
        }
65
#endif
66
        next = END_NOT_FOUND;
67
    } else {
68
        next = pnmctx.bytestream - pnmctx.bytestream_start
69
               + avpicture_get_size(avctx->pix_fmt, avctx->width, avctx->height);
70
        if (pnmctx.bytestream_start != buf)
71
            next -= pc->index;
72
        if (next > buf_size)
73
            next = END_NOT_FOUND;
74
    }
75

    
76
    if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
77
        *poutbuf      = NULL;
78
        *poutbuf_size = 0;
79
        return buf_size;
80
    }
81
    *poutbuf      = buf;
82
    *poutbuf_size = buf_size;
83
    return next;
84
}
85

    
86
AVCodecParser ff_pnm_parser = {
87
    { CODEC_ID_PGM, CODEC_ID_PGMYUV, CODEC_ID_PPM, CODEC_ID_PBM, CODEC_ID_PAM},
88
    sizeof(ParseContext),
89
    NULL,
90
    pnm_parse,
91
    ff_parse_close,
92
};