FFmpeg: libavformat/swfenc.c Source File

00001 /*
00002  * Flash Compatible Streaming Format muxer
00003  * Copyright (c) 2000 Fabrice Bellard
00004  * Copyright (c) 2003 Tinic Uro
00005  *
00006  * This file is part of FFmpeg.
00007  *
00008  * FFmpeg is free software; you can redistribute it and/or
00009  * modify it under the terms of the GNU Lesser General Public
00010  * License as published by the Free Software Foundation; either
00011  * version 2.1 of the License, or (at your option) any later version.
00012  *
00013  * FFmpeg is distributed in the hope that it will be useful,
00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00016  * Lesser General Public License for more details.
00017  *
00018  * You should have received a copy of the GNU Lesser General Public
00019  * License along with FFmpeg; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00021  */
00022 
00023 #include "libavcodec/put_bits.h"
00024 #include "avformat.h"
00025 #include "swf.h"
00026 
00027 static void put_swf_tag(AVFormatContext *s, int tag)
00028 {
00029     SWFContext *swf = s->priv_data;
00030     AVIOContext *pb = s->pb;
00031 
00032     swf->tag_pos = avio_tell(pb);
00033     swf->tag = tag;
00034     /* reserve some room for the tag */
00035     if (tag & TAG_LONG) {
00036         avio_wl16(pb, 0);
00037         avio_wl32(pb, 0);
00038     } else {
00039         avio_wl16(pb, 0);
00040     }
00041 }
00042 
00043 static void put_swf_end_tag(AVFormatContext *s)
00044 {
00045     SWFContext *swf = s->priv_data;
00046     AVIOContext *pb = s->pb;
00047     int64_t pos;
00048     int tag_len, tag;
00049 
00050     pos = avio_tell(pb);
00051     tag_len = pos - swf->tag_pos - 2;
00052     tag = swf->tag;
00053     avio_seek(pb, swf->tag_pos, SEEK_SET);
00054     if (tag & TAG_LONG) {
00055         tag &= ~TAG_LONG;
00056         avio_wl16(pb, (tag << 6) | 0x3f);
00057         avio_wl32(pb, tag_len - 4);
00058     } else {
00059         assert(tag_len < 0x3f);
00060         avio_wl16(pb, (tag << 6) | tag_len);
00061     }
00062     avio_seek(pb, pos, SEEK_SET);
00063 }
00064 
00065 static inline void max_nbits(int *nbits_ptr, int val)
00066 {
00067     int n;
00068 
00069     if (val == 0)
00070         return;
00071     val = abs(val);
00072     n = 1;
00073     while (val != 0) {
00074         n++;
00075         val >>= 1;
00076     }
00077     if (n > *nbits_ptr)
00078         *nbits_ptr = n;
00079 }
00080 
00081 static void put_swf_rect(AVIOContext *pb,
00082                          int xmin, int xmax, int ymin, int ymax)
00083 {
00084     PutBitContext p;
00085     uint8_t buf[256];
00086     int nbits, mask;
00087 
00088     init_put_bits(&p, buf, sizeof(buf));
00089 
00090     nbits = 0;
00091     max_nbits(&nbits, xmin);
00092     max_nbits(&nbits, xmax);
00093     max_nbits(&nbits, ymin);
00094     max_nbits(&nbits, ymax);
00095     mask = (1 << nbits) - 1;
00096 
00097     /* rectangle info */
00098     put_bits(&p, 5, nbits);
00099     put_bits(&p, nbits, xmin & mask);
00100     put_bits(&p, nbits, xmax & mask);
00101     put_bits(&p, nbits, ymin & mask);
00102     put_bits(&p, nbits, ymax & mask);
00103 
00104     flush_put_bits(&p);
00105     avio_write(pb, buf, put_bits_ptr(&p) - p.buf);
00106 }
00107 
00108 static void put_swf_line_edge(PutBitContext *pb, int dx, int dy)
00109 {
00110     int nbits, mask;
00111 
00112     put_bits(pb, 1, 1); /* edge */
00113     put_bits(pb, 1, 1); /* line select */
00114     nbits = 2;
00115     max_nbits(&nbits, dx);
00116     max_nbits(&nbits, dy);
00117 
00118     mask = (1 << nbits) - 1;
00119     put_bits(pb, 4, nbits - 2); /* 16 bits precision */
00120     if (dx == 0) {
00121         put_bits(pb, 1, 0);
00122         put_bits(pb, 1, 1);
00123         put_bits(pb, nbits, dy & mask);
00124     } else if (dy == 0) {
00125         put_bits(pb, 1, 0);
00126         put_bits(pb, 1, 0);
00127         put_bits(pb, nbits, dx & mask);
00128     } else {
00129         put_bits(pb, 1, 1);
00130         put_bits(pb, nbits, dx & mask);
00131         put_bits(pb, nbits, dy & mask);
00132     }
00133 }
00134 
00135 #define FRAC_BITS 16
00136 
00137 static void put_swf_matrix(AVIOContext *pb,
00138                            int a, int b, int c, int d, int tx, int ty)
00139 {
00140     PutBitContext p;
00141     uint8_t buf[256];
00142     int nbits;
00143 
00144     init_put_bits(&p, buf, sizeof(buf));
00145 
00146     put_bits(&p, 1, 1); /* a, d present */
00147     nbits = 1;
00148     max_nbits(&nbits, a);
00149     max_nbits(&nbits, d);
00150     put_bits(&p, 5, nbits); /* nb bits */
00151     put_bits(&p, nbits, a);
00152     put_bits(&p, nbits, d);
00153 
00154     put_bits(&p, 1, 1); /* b, c present */
00155     nbits = 1;
00156     max_nbits(&nbits, c);
00157     max_nbits(&nbits, b);
00158     put_bits(&p, 5, nbits); /* nb bits */
00159     put_bits(&p, nbits, c);
00160     put_bits(&p, nbits, b);
00161 
00162     nbits = 1;
00163     max_nbits(&nbits, tx);
00164     max_nbits(&nbits, ty);
00165     put_bits(&p, 5, nbits); /* nb bits */
00166     put_bits(&p, nbits, tx);
00167     put_bits(&p, nbits, ty);
00168 
00169     flush_put_bits(&p);
00170     avio_write(pb, buf, put_bits_ptr(&p) - p.buf);
00171 }
00172 
00173 static int swf_write_header(AVFormatContext *s)
00174 {
00175     SWFContext *swf = s->priv_data;
00176     AVIOContext *pb = s->pb;
00177     PutBitContext p;
00178     uint8_t buf1[256];
00179     int i, width, height, rate, rate_base;
00180     int version;
00181 
00182     swf->sound_samples = 0;
00183     swf->swf_frame_number = 0;
00184     swf->video_frame_number = 0;
00185 
00186     for(i=0;i<s->nb_streams;i++) {
00187         AVCodecContext *enc = s->streams[i]->codec;
00188         if (enc->codec_type == AVMEDIA_TYPE_AUDIO) {
00189             if (enc->codec_id == CODEC_ID_MP3) {
00190                 swf->audio_enc = enc;
00191                 swf->audio_fifo= av_fifo_alloc(AUDIO_FIFO_SIZE);
00192                 if (!swf->audio_fifo)
00193                     return AVERROR(ENOMEM);
00194             } else {
00195                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports MP3\n");
00196                 return -1;
00197             }
00198         } else {
00199             if (enc->codec_id == CODEC_ID_VP6F ||
00200                 enc->codec_id == CODEC_ID_FLV1 ||
00201                 enc->codec_id == CODEC_ID_MJPEG) {
00202                 swf->video_enc = enc;
00203             } else {
00204                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports VP6, FLV1 and MJPEG\n");
00205                 return -1;
00206             }
00207         }
00208     }
00209 
00210     if (!swf->video_enc) {
00211         /* currently, cannot work correctly if audio only */
00212         width = 320;
00213         height = 200;
00214         rate = 10;
00215         rate_base= 1;
00216     } else {
00217         width = swf->video_enc->width;
00218         height = swf->video_enc->height;
00219         rate = swf->video_enc->time_base.den;
00220         rate_base = swf->video_enc->time_base.num;
00221     }
00222 
00223     if (!swf->audio_enc)
00224         swf->samples_per_frame = (44100. * rate_base) / rate;
00225     else
00226         swf->samples_per_frame = (swf->audio_enc->sample_rate * rate_base) / rate;
00227 
00228     avio_write(pb, "FWS", 3);
00229 
00230     if (!strcmp("avm2", s->oformat->name))
00231         version = 9;
00232     else if (swf->video_enc && swf->video_enc->codec_id == CODEC_ID_VP6F)
00233         version = 8; /* version 8 and above support VP6 codec */
00234     else if (swf->video_enc && swf->video_enc->codec_id == CODEC_ID_FLV1)
00235         version = 6; /* version 6 and above support FLV1 codec */
00236     else
00237         version = 4; /* version 4 for mpeg audio support */
00238     avio_w8(pb, version);
00239 
00240     avio_wl32(pb, DUMMY_FILE_SIZE); /* dummy size
00241                                       (will be patched if not streamed) */
00242 
00243     put_swf_rect(pb, 0, width * 20, 0, height * 20);
00244     avio_wl16(pb, (rate * 256) / rate_base); /* frame rate */
00245     swf->duration_pos = avio_tell(pb);
00246     avio_wl16(pb, (uint16_t)(DUMMY_DURATION * (int64_t)rate / rate_base)); /* frame count */
00247 
00248     /* avm2/swf v9 (also v8?) files require a file attribute tag */
00249     if (version == 9) {
00250         put_swf_tag(s, TAG_FILEATTRIBUTES);
00251         avio_wl32(pb, 1<<3); /* set ActionScript v3/AVM2 flag */
00252         put_swf_end_tag(s);
00253     }
00254 
00255     /* define a shape with the jpeg inside */
00256     if (swf->video_enc && swf->video_enc->codec_id == CODEC_ID_MJPEG) {
00257         put_swf_tag(s, TAG_DEFINESHAPE);
00258 
00259         avio_wl16(pb, SHAPE_ID); /* ID of shape */
00260         /* bounding rectangle */
00261         put_swf_rect(pb, 0, width, 0, height);
00262         /* style info */
00263         avio_w8(pb, 1); /* one fill style */
00264         avio_w8(pb, 0x41); /* clipped bitmap fill */
00265         avio_wl16(pb, BITMAP_ID); /* bitmap ID */
00266         /* position of the bitmap */
00267         put_swf_matrix(pb, (int)(1.0 * (1 << FRAC_BITS)), 0,
00268                        0, (int)(1.0 * (1 << FRAC_BITS)), 0, 0);
00269         avio_w8(pb, 0); /* no line style */
00270 
00271         /* shape drawing */
00272         init_put_bits(&p, buf1, sizeof(buf1));
00273         put_bits(&p, 4, 1); /* one fill bit */
00274         put_bits(&p, 4, 0); /* zero line bit */
00275 
00276         put_bits(&p, 1, 0); /* not an edge */
00277         put_bits(&p, 5, FLAG_MOVETO | FLAG_SETFILL0);
00278         put_bits(&p, 5, 1); /* nbits */
00279         put_bits(&p, 1, 0); /* X */
00280         put_bits(&p, 1, 0); /* Y */
00281         put_bits(&p, 1, 1); /* set fill style 1 */
00282 
00283         /* draw the rectangle ! */
00284         put_swf_line_edge(&p, width, 0);
00285         put_swf_line_edge(&p, 0, height);
00286         put_swf_line_edge(&p, -width, 0);
00287         put_swf_line_edge(&p, 0, -height);
00288 
00289         /* end of shape */
00290         put_bits(&p, 1, 0); /* not an edge */
00291         put_bits(&p, 5, 0);
00292 
00293         flush_put_bits(&p);
00294         avio_write(pb, buf1, put_bits_ptr(&p) - p.buf);
00295 
00296         put_swf_end_tag(s);
00297     }
00298 
00299     if (swf->audio_enc && swf->audio_enc->codec_id == CODEC_ID_MP3) {
00300         int v = 0;
00301 
00302         /* start sound */
00303         put_swf_tag(s, TAG_STREAMHEAD2);
00304         switch(swf->audio_enc->sample_rate) {
00305         case 11025: v |= 1 << 2; break;
00306         case 22050: v |= 2 << 2; break;
00307         case 44100: v |= 3 << 2; break;
00308         default:
00309             /* not supported */
00310             av_log(s, AV_LOG_ERROR, "swf does not support that sample rate, choose from (44100, 22050, 11025).\n");
00311             return -1;
00312         }
00313         v |= 0x02; /* 16 bit playback */
00314         if (swf->audio_enc->channels == 2)
00315             v |= 0x01; /* stereo playback */
00316         avio_w8(s->pb, v);
00317         v |= 0x20; /* mp3 compressed */
00318         avio_w8(s->pb, v);
00319         avio_wl16(s->pb, swf->samples_per_frame);  /* avg samples per frame */
00320         avio_wl16(s->pb, 0);
00321 
00322         put_swf_end_tag(s);
00323     }
00324 
00325     avio_flush(s->pb);
00326     return 0;
00327 }
00328 
00329 static int swf_write_video(AVFormatContext *s,
00330                            AVCodecContext *enc, const uint8_t *buf, int size)
00331 {
00332     SWFContext *swf = s->priv_data;
00333     AVIOContext *pb = s->pb;
00334 
00335     /* Flash Player limit */
00336     if (swf->swf_frame_number == 16000)
00337         av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
00338 
00339     if (enc->codec_id == CODEC_ID_VP6F ||
00340         enc->codec_id == CODEC_ID_FLV1) {
00341         if (swf->video_frame_number == 0) {
00342             /* create a new video object */
00343             put_swf_tag(s, TAG_VIDEOSTREAM);
00344             avio_wl16(pb, VIDEO_ID);
00345             swf->vframes_pos = avio_tell(pb);
00346             avio_wl16(pb, 15000); /* hard flash player limit */
00347             avio_wl16(pb, enc->width);
00348             avio_wl16(pb, enc->height);
00349             avio_w8(pb, 0);
00350             avio_w8(pb,ff_codec_get_tag(swf_codec_tags,enc->codec_id));
00351             put_swf_end_tag(s);
00352 
00353             /* place the video object for the first time */
00354             put_swf_tag(s, TAG_PLACEOBJECT2);
00355             avio_w8(pb, 0x36);
00356             avio_wl16(pb, 1);
00357             avio_wl16(pb, VIDEO_ID);
00358             put_swf_matrix(pb, 1 << FRAC_BITS, 0, 0, 1 << FRAC_BITS, 0, 0);
00359             avio_wl16(pb, swf->video_frame_number);
00360             avio_write(pb, "video", 5);
00361             avio_w8(pb, 0x00);
00362             put_swf_end_tag(s);
00363         } else {
00364             /* mark the character for update */
00365             put_swf_tag(s, TAG_PLACEOBJECT2);
00366             avio_w8(pb, 0x11);
00367             avio_wl16(pb, 1);
00368             avio_wl16(pb, swf->video_frame_number);
00369             put_swf_end_tag(s);
00370         }
00371 
00372         /* set video frame data */
00373         put_swf_tag(s, TAG_VIDEOFRAME | TAG_LONG);
00374         avio_wl16(pb, VIDEO_ID);
00375         avio_wl16(pb, swf->video_frame_number++);
00376         avio_write(pb, buf, size);
00377         put_swf_end_tag(s);
00378     } else if (enc->codec_id == CODEC_ID_MJPEG) {
00379         if (swf->swf_frame_number > 0) {
00380             /* remove the shape */
00381             put_swf_tag(s, TAG_REMOVEOBJECT);
00382             avio_wl16(pb, SHAPE_ID); /* shape ID */
00383             avio_wl16(pb, 1); /* depth */
00384             put_swf_end_tag(s);
00385 
00386             /* free the bitmap */
00387             put_swf_tag(s, TAG_FREECHARACTER);
00388             avio_wl16(pb, BITMAP_ID);
00389             put_swf_end_tag(s);
00390         }
00391 
00392         put_swf_tag(s, TAG_JPEG2 | TAG_LONG);
00393 
00394         avio_wl16(pb, BITMAP_ID); /* ID of the image */
00395 
00396         /* a dummy jpeg header seems to be required */
00397         avio_wb32(pb, 0xffd8ffd9);
00398         /* write the jpeg image */
00399         avio_write(pb, buf, size);
00400 
00401         put_swf_end_tag(s);
00402 
00403         /* draw the shape */
00404 
00405         put_swf_tag(s, TAG_PLACEOBJECT);
00406         avio_wl16(pb, SHAPE_ID); /* shape ID */
00407         avio_wl16(pb, 1); /* depth */
00408         put_swf_matrix(pb, 20 << FRAC_BITS, 0, 0, 20 << FRAC_BITS, 0, 0);
00409         put_swf_end_tag(s);
00410     }
00411 
00412     swf->swf_frame_number++;
00413 
00414     /* streaming sound always should be placed just before showframe tags */
00415     if (swf->audio_enc && av_fifo_size(swf->audio_fifo)) {
00416         int frame_size = av_fifo_size(swf->audio_fifo);
00417         put_swf_tag(s, TAG_STREAMBLOCK | TAG_LONG);
00418         avio_wl16(pb, swf->sound_samples);
00419         avio_wl16(pb, 0); // seek samples
00420         av_fifo_generic_read(swf->audio_fifo, pb, frame_size, (void*)avio_write);
00421         put_swf_end_tag(s);
00422 
00423         /* update FIFO */
00424         swf->sound_samples = 0;
00425     }
00426 
00427     /* output the frame */
00428     put_swf_tag(s, TAG_SHOWFRAME);
00429     put_swf_end_tag(s);
00430 
00431     avio_flush(s->pb);
00432 
00433     return 0;
00434 }
00435 
00436 static int swf_write_audio(AVFormatContext *s,
00437                            AVCodecContext *enc, uint8_t *buf, int size)
00438 {
00439     SWFContext *swf = s->priv_data;
00440 
00441     /* Flash Player limit */
00442     if (swf->swf_frame_number == 16000)
00443         av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
00444 
00445     if (av_fifo_size(swf->audio_fifo) + size > AUDIO_FIFO_SIZE) {
00446         av_log(s, AV_LOG_ERROR, "audio fifo too small to mux audio essence\n");
00447         return -1;
00448     }
00449 
00450     av_fifo_generic_write(swf->audio_fifo, buf, size, NULL);
00451     swf->sound_samples += av_get_audio_frame_duration(enc, size);
00452 
00453     /* if audio only stream make sure we add swf frames */
00454     if (!swf->video_enc)
00455         swf_write_video(s, enc, 0, 0);
00456 
00457     return 0;
00458 }
00459 
00460 static int swf_write_packet(AVFormatContext *s, AVPacket *pkt)
00461 {
00462     AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
00463     if (codec->codec_type == AVMEDIA_TYPE_AUDIO)
00464         return swf_write_audio(s, codec, pkt->data, pkt->size);
00465     else
00466         return swf_write_video(s, codec, pkt->data, pkt->size);
00467 }
00468 
00469 static int swf_write_trailer(AVFormatContext *s)
00470 {
00471     SWFContext *swf = s->priv_data;
00472     AVIOContext *pb = s->pb;
00473     AVCodecContext *enc, *video_enc;
00474     int file_size, i;
00475 
00476     video_enc = NULL;
00477     for(i=0;i<s->nb_streams;i++) {
00478         enc = s->streams[i]->codec;
00479         if (enc->codec_type == AVMEDIA_TYPE_VIDEO)
00480             video_enc = enc;
00481         else
00482             av_fifo_free(swf->audio_fifo);
00483     }
00484 
00485     put_swf_tag(s, TAG_END);
00486     put_swf_end_tag(s);
00487 
00488     avio_flush(s->pb);
00489 
00490     /* patch file size and number of frames if not streamed */
00491     if (s->pb->seekable && video_enc) {
00492         file_size = avio_tell(pb);
00493         avio_seek(pb, 4, SEEK_SET);
00494         avio_wl32(pb, file_size);
00495         avio_seek(pb, swf->duration_pos, SEEK_SET);
00496         avio_wl16(pb, swf->video_frame_number);
00497         if (swf->vframes_pos) {
00498         avio_seek(pb, swf->vframes_pos, SEEK_SET);
00499         avio_wl16(pb, swf->video_frame_number);
00500         }
00501         avio_seek(pb, file_size, SEEK_SET);
00502     }
00503     return 0;
00504 }
00505 
00506 #if CONFIG_SWF_MUXER
00507 AVOutputFormat ff_swf_muxer = {
00508     .name              = "swf",
00509     .long_name         = NULL_IF_CONFIG_SMALL("Flash format"),
00510     .mime_type         = "application/x-shockwave-flash",
00511     .extensions        = "swf",
00512     .priv_data_size    = sizeof(SWFContext),
00513     .audio_codec       = CODEC_ID_MP3,
00514     .video_codec       = CODEC_ID_FLV1,
00515     .write_header      = swf_write_header,
00516     .write_packet      = swf_write_packet,
00517     .write_trailer     = swf_write_trailer,
00518     .flags             = AVFMT_TS_NONSTRICT,
00519 };
00520 #endif
00521 #if CONFIG_AVM2_MUXER
00522 AVOutputFormat ff_avm2_muxer = {
00523     .name              = "avm2",
00524     .long_name         = NULL_IF_CONFIG_SMALL("Flash 9 (AVM2) format"),
00525     .mime_type         = "application/x-shockwave-flash",
00526     .priv_data_size    = sizeof(SWFContext),
00527     .audio_codec       = CODEC_ID_MP3,
00528     .video_codec       = CODEC_ID_FLV1,
00529     .write_header      = swf_write_header,
00530     .write_packet      = swf_write_packet,
00531     .write_trailer     = swf_write_trailer,
00532     .flags             = AVFMT_TS_NONSTRICT,
00533 };
00534 #endif