| 1 | /* |
| 2 | * PNM image parser |
| 3 | * Copyright (c) 2002, 2003 Fabrice Bellard |
| 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 | */ |
| 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_ids = { AV_CODEC_ID_PGM, AV_CODEC_ID_PGMYUV, AV_CODEC_ID_PPM, |
| 88 | AV_CODEC_ID_PBM, AV_CODEC_ID_PAM }, |
| 89 | .priv_data_size = sizeof(ParseContext), |
| 90 | .parser_parse = pnm_parse, |
| 91 | .parser_close = ff_parse_close, |
| 92 | }; |