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libavformat/anm.c

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00001 /*
00002  * Deluxe Paint Animation demuxer
00003  * Copyright (c) 2009 Peter Ross
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00027 #include "libavutil/intreadwrite.h"
00028 #include "avformat.h"
00029 
00030 typedef struct {
00031     int base_record;
00032     unsigned int nb_records;
00033     int size;
00034 } Page;
00035 
00036 typedef struct {
00037     unsigned int nb_pages;    
00038     unsigned int nb_records;  
00039     int page_table_offset;
00040 #define MAX_PAGES  256        
00041     Page pt[MAX_PAGES];       
00042     int page;                 
00043     int record;               
00044 } AnmDemuxContext;
00045 
00046 #define LPF_TAG  MKTAG('L','P','F',' ')
00047 #define ANIM_TAG MKTAG('A','N','I','M')
00048 
00049 static int probe(AVProbeData *p)
00050 {
00051     /* verify tags and video dimensions */
00052     if (AV_RL32(&p->buf[0])  == LPF_TAG &&
00053         AV_RL32(&p->buf[16]) == ANIM_TAG &&
00054         AV_RL16(&p->buf[20]) && AV_RL16(&p->buf[22]))
00055         return AVPROBE_SCORE_MAX;
00056     return 0;
00057 }
00058 
00062 static int find_record(const AnmDemuxContext *anm, int record)
00063 {
00064     int i;
00065 
00066     if (record >= anm->nb_records)
00067         return AVERROR_EOF;
00068 
00069     for (i = 0; i < MAX_PAGES; i++) {
00070         const Page *p = &anm->pt[i];
00071         if (p->nb_records > 0 && record >= p->base_record && record < p->base_record + p->nb_records)
00072             return i;
00073     }
00074 
00075     return AVERROR_INVALIDDATA;
00076 }
00077 
00078 static int read_header(AVFormatContext *s,
00079                        AVFormatParameters *ap)
00080 {
00081     AnmDemuxContext *anm = s->priv_data;
00082     ByteIOContext *pb = s->pb;
00083     AVStream *st;
00084     int i, ret;
00085 
00086     url_fskip(pb, 4); /* magic number */
00087     if (get_le16(pb) != MAX_PAGES) {
00088         av_log_ask_for_sample(s, "max_pages != " AV_STRINGIFY(MAX_PAGES) "\n");
00089         return AVERROR_INVALIDDATA;
00090     }
00091 
00092     anm->nb_pages   = get_le16(pb);
00093     anm->nb_records = get_le32(pb);
00094     url_fskip(pb, 2); /* max records per page */
00095     anm->page_table_offset = get_le16(pb);
00096     if (get_le32(pb) != ANIM_TAG)
00097         return AVERROR_INVALIDDATA;
00098 
00099     /* video stream */
00100     st = av_new_stream(s, 0);
00101     if (!st)
00102         return AVERROR(ENOMEM);
00103     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00104     st->codec->codec_id   = CODEC_ID_ANM;
00105     st->codec->codec_tag  = 0; /* no fourcc */
00106     st->codec->width      = get_le16(pb);
00107     st->codec->height     = get_le16(pb);
00108     if (get_byte(pb) != 0)
00109         goto invalid;
00110     url_fskip(pb, 1); /* frame rate multiplier info */
00111 
00112     /* ignore last delta record (used for looping) */
00113     if (get_byte(pb))  /* has_last_delta */
00114         anm->nb_records = FFMAX(anm->nb_records - 1, 0);
00115 
00116     url_fskip(pb, 1); /* last_delta_valid */
00117 
00118     if (get_byte(pb) != 0)
00119         goto invalid;
00120 
00121     if (get_byte(pb) != 1)
00122         goto invalid;
00123 
00124     url_fskip(pb, 1); /* other recs per frame */
00125 
00126     if (get_byte(pb) != 1)
00127         goto invalid;
00128 
00129     url_fskip(pb, 32); /* record_types */
00130     st->nb_frames = get_le32(pb);
00131     av_set_pts_info(st, 64, 1, get_le16(pb));
00132     url_fskip(pb, 58);
00133 
00134     /* color cycling and palette data */
00135     st->codec->extradata_size = 16*8 + 4*256;
00136     st->codec->extradata      = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
00137     if (!st->codec->extradata) {
00138         ret = AVERROR(ENOMEM);
00139         goto close_and_return;
00140     }
00141     ret = get_buffer(pb, st->codec->extradata, st->codec->extradata_size);
00142     if (ret < 0)
00143         goto close_and_return;
00144 
00145     /* read page table */
00146     ret = url_fseek(pb, anm->page_table_offset, SEEK_SET);
00147     if (ret < 0)
00148         goto close_and_return;
00149 
00150     for (i = 0; i < MAX_PAGES; i++) {
00151         Page *p = &anm->pt[i];
00152         p->base_record = get_le16(pb);
00153         p->nb_records  = get_le16(pb);
00154         p->size        = get_le16(pb);
00155     }
00156 
00157     /* find page of first frame */
00158     anm->page = find_record(anm, 0);
00159     if (anm->page < 0) {
00160         ret = anm->page;
00161         goto close_and_return;
00162     }
00163 
00164     anm->record = -1;
00165     return 0;
00166 
00167 invalid:
00168     av_log_ask_for_sample(s, NULL);
00169     ret = AVERROR_INVALIDDATA;
00170 
00171 close_and_return:
00172     av_close_input_stream(s);
00173     return ret;
00174 }
00175 
00176 static int read_packet(AVFormatContext *s,
00177                        AVPacket *pkt)
00178 {
00179     AnmDemuxContext *anm = s->priv_data;
00180     ByteIOContext *pb = s->pb;
00181     Page *p;
00182     int tmp, record_size;
00183 
00184     if (url_feof(s->pb))
00185         return AVERROR(EIO);
00186 
00187     if (anm->page < 0)
00188         return anm->page;
00189 
00190 repeat:
00191     p = &anm->pt[anm->page];
00192 
00193     /* parse page header */
00194     if (anm->record < 0) {
00195         url_fseek(pb, anm->page_table_offset + MAX_PAGES*6 + (anm->page<<16), SEEK_SET);
00196         url_fskip(pb, 8 + 2*p->nb_records);
00197         anm->record = 0;
00198     }
00199 
00200     /* if we have fetched all records in this page, then find the
00201        next page and repeat */
00202     if (anm->record >= p->nb_records) {
00203         anm->page = find_record(anm, p->base_record + p->nb_records);
00204         if (anm->page < 0)
00205             return anm->page;
00206         anm->record = -1;
00207         goto repeat;
00208     }
00209 
00210     /* fetch record size */
00211     tmp = url_ftell(pb);
00212     url_fseek(pb, anm->page_table_offset + MAX_PAGES*6 + (anm->page<<16) +
00213               8 + anm->record * 2, SEEK_SET);
00214     record_size = get_le16(pb);
00215     url_fseek(pb, tmp, SEEK_SET);
00216 
00217     /* fetch record */
00218     pkt->size = av_get_packet(s->pb, pkt, record_size);
00219     if (pkt->size < 0)
00220         return pkt->size;
00221     if (p->base_record + anm->record == 0)
00222         pkt->flags |= AV_PKT_FLAG_KEY;
00223 
00224     anm->record++;
00225     return 0;
00226 }
00227 
00228 AVInputFormat anm_demuxer = {
00229     "anm",
00230     NULL_IF_CONFIG_SMALL("Deluxe Paint Animation"),
00231     sizeof(AnmDemuxContext),
00232     probe,
00233     read_header,
00234     read_packet,
00235 };

Generated on Fri Sep 16 2011 17:17:33 for FFmpeg by  doxygen 1.7.1