/* * AVI decoder. * Copyright (c) 2001 Fabrice Bellard. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "avformat.h" #include "avi.h" //#define DEBUG typedef struct AVIIndex { unsigned char tag[4]; unsigned int flags, pos, len; struct AVIIndex *next; } AVIIndex; typedef struct { INT64 movi_end; offset_t movi_list; AVIIndex *first, *last; } AVIContext; #ifdef DEBUG static void print_tag(const char *str, unsigned int tag, int size) { printf("%s: tag=%c%c%c%c size=0x%x\n", str, tag & 0xff, (tag >> 8) & 0xff, (tag >> 16) & 0xff, (tag >> 24) & 0xff, size); } #endif static int avi_read_header(AVFormatContext *s, AVFormatParameters *ap) { AVIContext *avi = s->priv_data; ByteIOContext *pb = &s->pb; UINT32 tag, tag1; int codec_type, stream_index, size, frame_period, bit_rate; int i; AVStream *st; /* check RIFF header */ tag = get_le32(pb); if (tag != MKTAG('R', 'I', 'F', 'F')) return -1; get_le32(pb); /* file size */ tag = get_le32(pb); if (tag != MKTAG('A', 'V', 'I', ' ')) return -1; /* first list tag */ stream_index = -1; codec_type = -1; frame_period = 0; for(;;) { if (url_feof(pb)) goto fail; tag = get_le32(pb); size = get_le32(pb); #ifdef DEBUG print_tag("tag", tag, size); #endif switch(tag) { case MKTAG('L', 'I', 'S', 'T'): /* ignored, except when start of video packets */ tag1 = get_le32(pb); #ifdef DEBUG print_tag("list", tag1, 0); #endif if (tag1 == MKTAG('m', 'o', 'v', 'i')) { avi->movi_end = url_ftell(pb) + size - 4; #ifdef DEBUG printf("movi end=%Lx\n", avi->movi_end); #endif goto end_of_header; } break; case MKTAG('a', 'v', 'i', 'h'): /* avi header */ /* using frame_period is bad idea */ frame_period = get_le32(pb); bit_rate = get_le32(pb) * 8; url_fskip(pb, 4 * 4); s->nb_streams = get_le32(pb); for(i=0;inb_streams;i++) { AVStream *st = av_mallocz(sizeof(AVStream)); if (!st) goto fail; avcodec_get_context_defaults(&st->codec); s->streams[i] = st; } url_fskip(pb, size - 7 * 4); break; case MKTAG('s', 't', 'r', 'h'): /* stream header */ stream_index++; tag1 = get_le32(pb); switch(tag1) { case MKTAG('v', 'i', 'd', 's'): codec_type = CODEC_TYPE_VIDEO; get_le32(pb); /* codec tag */ get_le32(pb); /* flags */ get_le16(pb); /* priority */ get_le16(pb); /* language */ get_le32(pb); /* XXX: initial frame ? */ get_le32(pb); /* scale */ get_le32(pb); /* rate */ size -= 6 * 4; break; case MKTAG('a', 'u', 'd', 's'): codec_type = CODEC_TYPE_AUDIO; /* nothing really useful */ } url_fskip(pb, size - 4); break; case MKTAG('s', 't', 'r', 'f'): /* stream header */ if (stream_index >= s->nb_streams) { url_fskip(pb, size); } else { st = s->streams[stream_index]; switch(codec_type) { case CODEC_TYPE_VIDEO: get_le32(pb); /* size */ st->codec.width = get_le32(pb); st->codec.height = get_le32(pb); if (frame_period) st->codec.frame_rate = (INT64_C(1000000) * FRAME_RATE_BASE) / frame_period; else st->codec.frame_rate = 25 * FRAME_RATE_BASE; get_le16(pb); /* panes */ get_le16(pb); /* depth */ tag1 = get_le32(pb); #ifdef DEBUG print_tag("video", tag1, 0); #endif st->codec.codec_type = CODEC_TYPE_VIDEO; st->codec.codec_tag = tag1; st->codec.codec_id = codec_get_id(codec_bmp_tags, tag1); url_fskip(pb, size - 5 * 4); break; case CODEC_TYPE_AUDIO: get_wav_header(pb, &st->codec, (size >= 18)); if (size%2) /* 2-aligned (fix for Stargate SG-1 - 3x18 - Shades of Grey.avi) */ url_fskip(pb, 1); break; default: url_fskip(pb, size); break; } } break; default: /* skip tag */ size += (size & 1); url_fskip(pb, size); break; } } end_of_header: /* check stream number */ if (stream_index != s->nb_streams - 1) { fail: for(i=0;inb_streams;i++) { av_freep(&s->streams[i]); } return -1; } return 0; } static int avi_read_packet(AVFormatContext *s, AVPacket *pkt) { AVIContext *avi = s->priv_data; ByteIOContext *pb = &s->pb; int n, d1, d2, size; for(;;) { if (url_feof(pb) || url_ftell(pb) >= avi->movi_end) return -1; d1 = get_byte(pb) - '0'; d2 = get_byte(pb) - '0'; if (d1 < 0 || d1 > 9 || d2 < 0 || d2 > 9) continue; n = d1 * 10 + d2; if (n < 0 || n >= s->nb_streams) continue; d1 = get_byte(pb); d2 = get_byte(pb); if ((d1 == 'd' && d2 == 'c') || (d1 == 'w' && d2 == 'b')) break; } size = get_le32(pb); av_new_packet(pkt, size); pkt->stream_index = n; get_buffer(pb, pkt->data, pkt->size); if (size & 1) get_byte(pb); return 0; } static int avi_read_close(AVFormatContext *s) { return 0; } static int avi_probe(AVProbeData *p) { /* check file header */ if (p->buf_size <= 32) return 0; if (p->buf[0] == 'R' && p->buf[1] == 'I' && p->buf[2] == 'F' && p->buf[3] == 'F' && p->buf[8] == 'A' && p->buf[9] == 'V' && p->buf[10] == 'I' && p->buf[11] == ' ') return AVPROBE_SCORE_MAX; else return 0; } static AVInputFormat avi_iformat = { "avi", "avi format", sizeof(AVIContext), avi_probe, avi_read_header, avi_read_packet, avi_read_close, }; int avidec_init(void) { av_register_input_format(&avi_iformat); return 0; }