/* * Flash Compatible Streaming Format * Copyright (c) 2000 Gerard Lantau. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include "avformat.h" /* should have a generic way to indicate probable size */ #define DUMMY_FILE_SIZE (100 * 1024 * 1024) #define DUMMY_DURATION 600 /* in seconds */ #define TAG_END 0 #define TAG_SHOWFRAME 1 #define TAG_DEFINESHAPE 2 #define TAG_FREECHARACTER 3 #define TAG_PLACEOBJECT 4 #define TAG_REMOVEOBJECT 5 #define TAG_STREAMHEAD 18 #define TAG_STREAMBLOCK 19 #define TAG_JPEG2 21 #define TAG_LONG 0x100 /* flags for shape definition */ #define FLAG_MOVETO 0x01 #define FLAG_SETFILL0 0x02 #define FLAG_SETFILL1 0x04 /* character id used */ #define BITMAP_ID 0 #define SHAPE_ID 1 typedef struct { offset_t duration_pos; offset_t tag_pos; int tag; } SWFContext; static void put_swf_tag(AVFormatContext *s, int tag) { SWFContext *swf = s->priv_data; ByteIOContext *pb = &s->pb; swf->tag_pos = url_ftell(pb); swf->tag = tag; /* reserve some room for the tag */ if (tag & TAG_LONG) { put_le16(pb, 0); put_le32(pb, 0); } else { put_le16(pb, 0); } } static void put_swf_end_tag(AVFormatContext *s) { SWFContext *swf = s->priv_data; ByteIOContext *pb = &s->pb; offset_t pos; int tag_len, tag; pos = url_ftell(pb); tag_len = pos - swf->tag_pos - 2; tag = swf->tag; url_fseek(pb, swf->tag_pos, SEEK_SET); if (tag & TAG_LONG) { tag &= ~TAG_LONG; put_le16(pb, (tag << 6) | 0x3f); put_le32(pb, tag_len - 4); } else { assert(tag_len < 0x3f); put_le16(pb, (tag << 6) | tag_len); } url_fseek(pb, pos, SEEK_SET); } static inline void max_nbits(int *nbits_ptr, int val) { int n; if (val == 0) return; val = abs(val); n = 1; while (val != 0) { n++; val >>= 1; } if (n > *nbits_ptr) *nbits_ptr = n; } static void put_swf_rect(ByteIOContext *pb, int xmin, int xmax, int ymin, int ymax) { PutBitContext p; UINT8 buf[256]; int nbits, mask; init_put_bits(&p, buf, sizeof(buf), NULL, NULL); nbits = 0; max_nbits(&nbits, xmin); max_nbits(&nbits, xmax); max_nbits(&nbits, ymin); max_nbits(&nbits, ymax); mask = (1 << nbits) - 1; /* rectangle info */ put_bits(&p, 5, nbits); put_bits(&p, nbits, xmin & mask); put_bits(&p, nbits, xmax & mask); put_bits(&p, nbits, ymin & mask); put_bits(&p, nbits, ymax & mask); flush_put_bits(&p); put_buffer(pb, buf, p.buf_ptr - p.buf); } static void put_swf_line_edge(PutBitContext *pb, int dx, int dy) { int nbits, mask; put_bits(pb, 1, 1); /* edge */ put_bits(pb, 1, 1); /* line select */ nbits = 2; max_nbits(&nbits, dx); max_nbits(&nbits, dy); mask = (1 << nbits) - 1; put_bits(pb, 4, nbits - 2); /* 16 bits precision */ if (dx == 0) { put_bits(pb, 1, 0); put_bits(pb, 1, 1); put_bits(pb, nbits, dy & mask); } else if (dy == 0) { put_bits(pb, 1, 0); put_bits(pb, 1, 0); put_bits(pb, nbits, dx & mask); } else { put_bits(pb, 1, 1); put_bits(pb, nbits, dx & mask); put_bits(pb, nbits, dy & mask); } } #define FRAC_BITS 16 /* put matrix (not size optimized */ static void put_swf_matrix(ByteIOContext *pb, int a, int b, int c, int d, int tx, int ty) { PutBitContext p; UINT8 buf[256]; init_put_bits(&p, buf, sizeof(buf), NULL, NULL); put_bits(&p, 1, 1); /* a, d present */ put_bits(&p, 5, 20); /* nb bits */ put_bits(&p, 20, a); put_bits(&p, 20, d); put_bits(&p, 1, 1); /* b, c present */ put_bits(&p, 5, 20); /* nb bits */ put_bits(&p, 20, c); put_bits(&p, 20, b); put_bits(&p, 5, 20); /* nb bits */ put_bits(&p, 20, tx); put_bits(&p, 20, ty); flush_put_bits(&p); put_buffer(pb, buf, p.buf_ptr - p.buf); } /* XXX: handle audio only */ static int swf_write_header(AVFormatContext *s) { SWFContext *swf; ByteIOContext *pb = &s->pb; AVCodecContext *enc, *audio_enc, *video_enc; PutBitContext p; UINT8 buf1[256]; int i, width, height, rate; swf = malloc(sizeof(SWFContext)); if (!swf) return -1; s->priv_data = swf; video_enc = NULL; audio_enc = NULL; for(i=0;i<s->nb_streams;i++) { enc = &s->streams[i]->codec; if (enc->codec_type == CODEC_TYPE_AUDIO) audio_enc = enc; else video_enc = enc; } if (!video_enc) { /* currenty, cannot work correctly if audio only */ width = 320; height = 200; rate = 10 * FRAME_RATE_BASE; } else { width = video_enc->width; height = video_enc->height; rate = video_enc->frame_rate; } put_tag(pb, "FWS"); put_byte(pb, 4); /* version (should use 4 for mpeg audio support) */ put_le32(pb, DUMMY_FILE_SIZE); /* dummy size (will be patched if not streamed) */ put_swf_rect(pb, 0, width, 0, height); put_le16(pb, (rate * 256) / FRAME_RATE_BASE); /* frame rate */ swf->duration_pos = url_ftell(pb); put_le16(pb, (UINT16)(DUMMY_DURATION * (INT64)rate / FRAME_RATE_BASE)); /* frame count */ /* define a shape with the jpeg inside */ put_swf_tag(s, TAG_DEFINESHAPE); put_le16(pb, SHAPE_ID); /* ID of shape */ /* bounding rectangle */ put_swf_rect(pb, 0, width, 0, height); /* style info */ put_byte(pb, 1); /* one fill style */ put_byte(pb, 0x41); /* clipped bitmap fill */ put_le16(pb, BITMAP_ID); /* bitmap ID */ /* position of the bitmap */ put_swf_matrix(pb, (int)(1.0 * (1 << FRAC_BITS)), 0, 0, (int)(1.0 * (1 << FRAC_BITS)), 0, 0); put_byte(pb, 0); /* no line style */ /* shape drawing */ init_put_bits(&p, buf1, sizeof(buf1), NULL, NULL); put_bits(&p, 4, 1); /* one fill bit */ put_bits(&p, 4, 0); /* zero line bit */ put_bits(&p, 1, 0); /* not an edge */ put_bits(&p, 5, FLAG_MOVETO | FLAG_SETFILL0); put_bits(&p, 5, 1); /* nbits */ put_bits(&p, 1, 0); /* X */ put_bits(&p, 1, 0); /* Y */ put_bits(&p, 1, 1); /* set fill style 1 */ /* draw the rectangle ! */ put_swf_line_edge(&p, width, 0); put_swf_line_edge(&p, 0, height); put_swf_line_edge(&p, -width, 0); put_swf_line_edge(&p, 0, -height); /* end of shape */ put_bits(&p, 1, 0); /* not an edge */ put_bits(&p, 5, 0); flush_put_bits(&p); put_buffer(pb, buf1, p.buf_ptr - p.buf); put_swf_end_tag(s); if (audio_enc) { int v; /* start sound */ v = 0; switch(audio_enc->sample_rate) { case 11025: v |= 1 << 2; break; case 22050: v |= 2 << 2; break; case 44100: v |= 3 << 2; break; default: /* not supported */ free(swf); return -1; } if (audio_enc->channels == 2) v |= 1; v |= 0x20; /* mp3 compressed */ v |= 0x02; /* 16 bits */ put_swf_tag(s, TAG_STREAMHEAD); put_byte(&s->pb, 0); put_byte(&s->pb, v); put_le16(&s->pb, (audio_enc->sample_rate * FRAME_RATE_BASE) / rate); /* avg samples per frame */ put_swf_end_tag(s); } put_flush_packet(&s->pb); return 0; } static int swf_write_video(AVFormatContext *s, AVCodecContext *enc, UINT8 *buf, int size) { ByteIOContext *pb = &s->pb; static int tag_id = 0; if (enc->frame_number > 1) { /* remove the shape */ put_swf_tag(s, TAG_REMOVEOBJECT); put_le16(pb, SHAPE_ID); /* shape ID */ put_le16(pb, 1); /* depth */ put_swf_end_tag(s); /* free the bitmap */ put_swf_tag(s, TAG_FREECHARACTER); put_le16(pb, BITMAP_ID); put_swf_end_tag(s); } put_swf_tag(s, TAG_JPEG2 | TAG_LONG); put_le16(pb, tag_id); /* ID of the image */ /* a dummy jpeg header seems to be required */ put_byte(pb, 0xff); put_byte(pb, 0xd8); put_byte(pb, 0xff); put_byte(pb, 0xd9); /* write the jpeg image */ put_buffer(pb, buf, size); put_swf_end_tag(s); /* draw the shape */ put_swf_tag(s, TAG_PLACEOBJECT); put_le16(pb, SHAPE_ID); /* shape ID */ put_le16(pb, 1); /* depth */ put_swf_matrix(pb, 1 << FRAC_BITS, 0, 0, 1 << FRAC_BITS, 0, 0); put_swf_end_tag(s); /* output the frame */ put_swf_tag(s, TAG_SHOWFRAME); put_swf_end_tag(s); put_flush_packet(&s->pb); return 0; } static int swf_write_audio(AVFormatContext *s, UINT8 *buf, int size) { ByteIOContext *pb = &s->pb; put_swf_tag(s, TAG_STREAMBLOCK | TAG_LONG); put_buffer(pb, buf, size); put_swf_end_tag(s); put_flush_packet(&s->pb); return 0; } static int swf_write_packet(AVFormatContext *s, int stream_index, UINT8 *buf, int size) { AVCodecContext *codec = &s->streams[stream_index]->codec; if (codec->codec_type == CODEC_TYPE_AUDIO) return swf_write_audio(s, buf, size); else return swf_write_video(s, codec, buf, size); } static int swf_write_trailer(AVFormatContext *s) { SWFContext *swf = s->priv_data; ByteIOContext *pb = &s->pb; AVCodecContext *enc, *video_enc; int file_size, i; video_enc = NULL; for(i=0;i<s->nb_streams;i++) { enc = &s->streams[i]->codec; if (enc->codec_type == CODEC_TYPE_VIDEO) video_enc = enc; } put_swf_tag(s, TAG_END); put_swf_end_tag(s); put_flush_packet(&s->pb); /* patch file size and number of frames if not streamed */ if (!url_is_streamed(&s->pb) && video_enc) { file_size = url_ftell(pb); url_fseek(pb, 4, SEEK_SET); put_le32(pb, file_size); url_fseek(pb, swf->duration_pos, SEEK_SET); put_le16(pb, video_enc->frame_number); } free(swf); return 0; } /***********************************/ /* just to extract MP3 from swf */ static int get_swf_tag(ByteIOContext *pb, int *len_ptr) { int tag, len; if (url_feof(pb)) return -1; tag = get_le16(pb); len = tag & 0x3f; tag = tag >> 6; if (len == 0x3f) { len = get_le32(pb); } *len_ptr = len; return tag; } static int swf_read_header(AVFormatContext *s, AVFormatParameters *ap) { ByteIOContext *pb = &s->pb; int nbits, len, frame_rate, tag, v; AVStream *st; if ((get_be32(pb) & 0xffffff00) != MKBETAG('F', 'W', 'S', 0)) return -EIO; get_le32(pb); /* skip rectangle size */ nbits = get_byte(pb) >> 3; len = (4 * nbits - 3 + 7) / 8; url_fskip(pb, len); frame_rate = get_le16(pb); get_le16(pb); /* frame count */ for(;;) { tag = get_swf_tag(pb, &len); if (tag < 0) { fprintf(stderr, "No streaming found in SWF\n"); return -EIO; } if (tag == TAG_STREAMHEAD) { /* streaming found */ get_byte(pb); v = get_byte(pb); get_le16(pb); /* if mp3 streaming found, OK */ if ((v & 0x20) != 0) { st = av_mallocz(sizeof(AVStream)); if (!st) return -ENOMEM; if (v & 0x01) st->codec.channels = 2; else st->codec.channels = 1; s->nb_streams = 1; s->streams[0] = st; switch((v>> 2) & 0x03) { case 1: st->codec.sample_rate = 11025; break; case 2: st->codec.sample_rate = 22050; break; case 3: st->codec.sample_rate = 44100; break; default: free(st); return -EIO; } st->codec.codec_type = CODEC_TYPE_AUDIO; st->codec.codec_id = CODEC_ID_MP2; break; } } else { url_fskip(pb, len); } } return 0; } static int swf_read_packet(AVFormatContext *s, AVPacket *pkt) { ByteIOContext *pb = &s->pb; int tag, len; for(;;) { tag = get_swf_tag(pb, &len); if (tag < 0) return -EIO; if (tag == TAG_STREAMBLOCK) { av_new_packet(pkt, len); get_buffer(pb, pkt->data, pkt->size); break; } else { url_fskip(pb, len); } } return 0; } static int swf_read_close(AVFormatContext *s) { return 0; } AVFormat swf_format = { "swf", "Flash format", "application/x-shockwave-flash", "swf", CODEC_ID_MP2, CODEC_ID_MJPEG, swf_write_header, swf_write_packet, swf_write_trailer, swf_read_header, swf_read_packet, swf_read_close, };