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                 if (!enc->frame_size) {
00191                     av_log(s, AV_LOG_ERROR, "audio frame size not set\n");
00192                     return -1;
00193                 }
00194                 swf->audio_enc = enc;
00195                 swf->audio_fifo= av_fifo_alloc(AUDIO_FIFO_SIZE);
00196                 if (!swf->audio_fifo)
00197                     return AVERROR(ENOMEM);
00198             } else {
00199                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports MP3\n");
00200                 return -1;
00201             }
00202         } else {
00203             if (enc->codec_id == CODEC_ID_VP6F ||
00204                 enc->codec_id == CODEC_ID_FLV1 ||
00205                 enc->codec_id == CODEC_ID_MJPEG) {
00206                 swf->video_enc = enc;
00207             } else {
00208                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports VP6, FLV1 and MJPEG\n");
00209                 return -1;
00210             }
00211         }
00212     }
00213 
00214     if (!swf->video_enc) {
00215         /* currently, cannot work correctly if audio only */
00216         width = 320;
00217         height = 200;
00218         rate = 10;
00219         rate_base= 1;
00220     } else {
00221         width = swf->video_enc->width;
00222         height = swf->video_enc->height;
00223         rate = swf->video_enc->time_base.den;
00224         rate_base = swf->video_enc->time_base.num;
00225     }
00226 
00227     if (!swf->audio_enc)
00228         swf->samples_per_frame = (44100. * rate_base) / rate;
00229     else
00230         swf->samples_per_frame = (swf->audio_enc->sample_rate * rate_base) / rate;
00231 
00232     avio_write(pb, "FWS", 3);
00233 
00234     if (!strcmp("avm2", s->oformat->name))
00235         version = 9;
00236     else if (swf->video_enc && swf->video_enc->codec_id == CODEC_ID_VP6F)
00237         version = 8; /* version 8 and above support VP6 codec */
00238     else if (swf->video_enc && swf->video_enc->codec_id == CODEC_ID_FLV1)
00239         version = 6; /* version 6 and above support FLV1 codec */
00240     else
00241         version = 4; /* version 4 for mpeg audio support */
00242     avio_w8(pb, version);
00243 
00244     avio_wl32(pb, DUMMY_FILE_SIZE); /* dummy size
00245                                       (will be patched if not streamed) */
00246 
00247     put_swf_rect(pb, 0, width * 20, 0, height * 20);
00248     avio_wl16(pb, (rate * 256) / rate_base); /* frame rate */
00249     swf->duration_pos = avio_tell(pb);
00250     avio_wl16(pb, (uint16_t)(DUMMY_DURATION * (int64_t)rate / rate_base)); /* frame count */
00251 
00252     /* avm2/swf v9 (also v8?) files require a file attribute tag */
00253     if (version == 9) {
00254         put_swf_tag(s, TAG_FILEATTRIBUTES);
00255         avio_wl32(pb, 1<<3); /* set ActionScript v3/AVM2 flag */
00256         put_swf_end_tag(s);
00257     }
00258 
00259     /* define a shape with the jpeg inside */
00260     if (swf->video_enc && swf->video_enc->codec_id == CODEC_ID_MJPEG) {
00261         put_swf_tag(s, TAG_DEFINESHAPE);
00262 
00263         avio_wl16(pb, SHAPE_ID); /* ID of shape */
00264         /* bounding rectangle */
00265         put_swf_rect(pb, 0, width, 0, height);
00266         /* style info */
00267         avio_w8(pb, 1); /* one fill style */
00268         avio_w8(pb, 0x41); /* clipped bitmap fill */
00269         avio_wl16(pb, BITMAP_ID); /* bitmap ID */
00270         /* position of the bitmap */
00271         put_swf_matrix(pb, (int)(1.0 * (1 << FRAC_BITS)), 0,
00272                        0, (int)(1.0 * (1 << FRAC_BITS)), 0, 0);
00273         avio_w8(pb, 0); /* no line style */
00274 
00275         /* shape drawing */
00276         init_put_bits(&p, buf1, sizeof(buf1));
00277         put_bits(&p, 4, 1); /* one fill bit */
00278         put_bits(&p, 4, 0); /* zero line bit */
00279 
00280         put_bits(&p, 1, 0); /* not an edge */
00281         put_bits(&p, 5, FLAG_MOVETO | FLAG_SETFILL0);
00282         put_bits(&p, 5, 1); /* nbits */
00283         put_bits(&p, 1, 0); /* X */
00284         put_bits(&p, 1, 0); /* Y */
00285         put_bits(&p, 1, 1); /* set fill style 1 */
00286 
00287         /* draw the rectangle ! */
00288         put_swf_line_edge(&p, width, 0);
00289         put_swf_line_edge(&p, 0, height);
00290         put_swf_line_edge(&p, -width, 0);
00291         put_swf_line_edge(&p, 0, -height);
00292 
00293         /* end of shape */
00294         put_bits(&p, 1, 0); /* not an edge */
00295         put_bits(&p, 5, 0);
00296 
00297         flush_put_bits(&p);
00298         avio_write(pb, buf1, put_bits_ptr(&p) - p.buf);
00299 
00300         put_swf_end_tag(s);
00301     }
00302 
00303     if (swf->audio_enc && swf->audio_enc->codec_id == CODEC_ID_MP3) {
00304         int v = 0;
00305 
00306         /* start sound */
00307         put_swf_tag(s, TAG_STREAMHEAD2);
00308         switch(swf->audio_enc->sample_rate) {
00309         case 11025: v |= 1 << 2; break;
00310         case 22050: v |= 2 << 2; break;
00311         case 44100: v |= 3 << 2; break;
00312         default:
00313             /* not supported */
00314             av_log(s, AV_LOG_ERROR, "swf does not support that sample rate, choose from (44100, 22050, 11025).\n");
00315             return -1;
00316         }
00317         v |= 0x02; /* 16 bit playback */
00318         if (swf->audio_enc->channels == 2)
00319             v |= 0x01; /* stereo playback */
00320         avio_w8(s->pb, v);
00321         v |= 0x20; /* mp3 compressed */
00322         avio_w8(s->pb, v);
00323         avio_wl16(s->pb, swf->samples_per_frame);  /* avg samples per frame */
00324         avio_wl16(s->pb, 0);
00325 
00326         put_swf_end_tag(s);
00327     }
00328 
00329     avio_flush(s->pb);
00330     return 0;
00331 }
00332 
00333 static int swf_write_video(AVFormatContext *s,
00334                            AVCodecContext *enc, const uint8_t *buf, int size)
00335 {
00336     SWFContext *swf = s->priv_data;
00337     AVIOContext *pb = s->pb;
00338 
00339     /* Flash Player limit */
00340     if (swf->swf_frame_number == 16000)
00341         av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
00342 
00343     if (enc->codec_id == CODEC_ID_VP6F ||
00344         enc->codec_id == CODEC_ID_FLV1) {
00345         if (swf->video_frame_number == 0) {
00346             /* create a new video object */
00347             put_swf_tag(s, TAG_VIDEOSTREAM);
00348             avio_wl16(pb, VIDEO_ID);
00349             swf->vframes_pos = avio_tell(pb);
00350             avio_wl16(pb, 15000); /* hard flash player limit */
00351             avio_wl16(pb, enc->width);
00352             avio_wl16(pb, enc->height);
00353             avio_w8(pb, 0);
00354             avio_w8(pb,ff_codec_get_tag(swf_codec_tags,enc->codec_id));
00355             put_swf_end_tag(s);
00356 
00357             /* place the video object for the first time */
00358             put_swf_tag(s, TAG_PLACEOBJECT2);
00359             avio_w8(pb, 0x36);
00360             avio_wl16(pb, 1);
00361             avio_wl16(pb, VIDEO_ID);
00362             put_swf_matrix(pb, 1 << FRAC_BITS, 0, 0, 1 << FRAC_BITS, 0, 0);
00363             avio_wl16(pb, swf->video_frame_number);
00364             avio_write(pb, "video", 5);
00365             avio_w8(pb, 0x00);
00366             put_swf_end_tag(s);
00367         } else {
00368             /* mark the character for update */
00369             put_swf_tag(s, TAG_PLACEOBJECT2);
00370             avio_w8(pb, 0x11);
00371             avio_wl16(pb, 1);
00372             avio_wl16(pb, swf->video_frame_number);
00373             put_swf_end_tag(s);
00374         }
00375 
00376         /* set video frame data */
00377         put_swf_tag(s, TAG_VIDEOFRAME | TAG_LONG);
00378         avio_wl16(pb, VIDEO_ID);
00379         avio_wl16(pb, swf->video_frame_number++);
00380         avio_write(pb, buf, size);
00381         put_swf_end_tag(s);
00382     } else if (enc->codec_id == CODEC_ID_MJPEG) {
00383         if (swf->swf_frame_number > 0) {
00384             /* remove the shape */
00385             put_swf_tag(s, TAG_REMOVEOBJECT);
00386             avio_wl16(pb, SHAPE_ID); /* shape ID */
00387             avio_wl16(pb, 1); /* depth */
00388             put_swf_end_tag(s);
00389 
00390             /* free the bitmap */
00391             put_swf_tag(s, TAG_FREECHARACTER);
00392             avio_wl16(pb, BITMAP_ID);
00393             put_swf_end_tag(s);
00394         }
00395 
00396         put_swf_tag(s, TAG_JPEG2 | TAG_LONG);
00397 
00398         avio_wl16(pb, BITMAP_ID); /* ID of the image */
00399 
00400         /* a dummy jpeg header seems to be required */
00401         avio_wb32(pb, 0xffd8ffd9);
00402         /* write the jpeg image */
00403         avio_write(pb, buf, size);
00404 
00405         put_swf_end_tag(s);
00406 
00407         /* draw the shape */
00408 
00409         put_swf_tag(s, TAG_PLACEOBJECT);
00410         avio_wl16(pb, SHAPE_ID); /* shape ID */
00411         avio_wl16(pb, 1); /* depth */
00412         put_swf_matrix(pb, 20 << FRAC_BITS, 0, 0, 20 << FRAC_BITS, 0, 0);
00413         put_swf_end_tag(s);
00414     }
00415 
00416     swf->swf_frame_number++;
00417 
00418     /* streaming sound always should be placed just before showframe tags */
00419     if (swf->audio_enc && av_fifo_size(swf->audio_fifo)) {
00420         int frame_size = av_fifo_size(swf->audio_fifo);
00421         put_swf_tag(s, TAG_STREAMBLOCK | TAG_LONG);
00422         avio_wl16(pb, swf->sound_samples);
00423         avio_wl16(pb, 0); // seek samples
00424         av_fifo_generic_read(swf->audio_fifo, pb, frame_size, (void*)avio_write);
00425         put_swf_end_tag(s);
00426 
00427         /* update FIFO */
00428         swf->sound_samples = 0;
00429     }
00430 
00431     /* output the frame */
00432     put_swf_tag(s, TAG_SHOWFRAME);
00433     put_swf_end_tag(s);
00434 
00435     avio_flush(s->pb);
00436 
00437     return 0;
00438 }
00439 
00440 static int swf_write_audio(AVFormatContext *s,
00441                            AVCodecContext *enc, uint8_t *buf, int size)
00442 {
00443     SWFContext *swf = s->priv_data;
00444 
00445     /* Flash Player limit */
00446     if (swf->swf_frame_number == 16000)
00447         av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
00448 
00449     if (av_fifo_size(swf->audio_fifo) + size > AUDIO_FIFO_SIZE) {
00450         av_log(s, AV_LOG_ERROR, "audio fifo too small to mux audio essence\n");
00451         return -1;
00452     }
00453 
00454     av_fifo_generic_write(swf->audio_fifo, buf, size, NULL);
00455     swf->sound_samples += enc->frame_size;
00456 
00457     /* if audio only stream make sure we add swf frames */
00458     if (!swf->video_enc)
00459         swf_write_video(s, enc, 0, 0);
00460 
00461     return 0;
00462 }
00463 
00464 static int swf_write_packet(AVFormatContext *s, AVPacket *pkt)
00465 {
00466     AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
00467     if (codec->codec_type == AVMEDIA_TYPE_AUDIO)
00468         return swf_write_audio(s, codec, pkt->data, pkt->size);
00469     else
00470         return swf_write_video(s, codec, pkt->data, pkt->size);
00471 }
00472 
00473 static int swf_write_trailer(AVFormatContext *s)
00474 {
00475     SWFContext *swf = s->priv_data;
00476     AVIOContext *pb = s->pb;
00477     AVCodecContext *enc, *video_enc;
00478     int file_size, i;
00479 
00480     video_enc = NULL;
00481     for(i=0;i<s->nb_streams;i++) {
00482         enc = s->streams[i]->codec;
00483         if (enc->codec_type == AVMEDIA_TYPE_VIDEO)
00484             video_enc = enc;
00485         else
00486             av_fifo_free(swf->audio_fifo);
00487     }
00488 
00489     put_swf_tag(s, TAG_END);
00490     put_swf_end_tag(s);
00491 
00492     avio_flush(s->pb);
00493 
00494     /* patch file size and number of frames if not streamed */
00495     if (s->pb->seekable && video_enc) {
00496         file_size = avio_tell(pb);
00497         avio_seek(pb, 4, SEEK_SET);
00498         avio_wl32(pb, file_size);
00499         avio_seek(pb, swf->duration_pos, SEEK_SET);
00500         avio_wl16(pb, swf->video_frame_number);
00501         if (swf->vframes_pos) {
00502         avio_seek(pb, swf->vframes_pos, SEEK_SET);
00503         avio_wl16(pb, swf->video_frame_number);
00504         }
00505         avio_seek(pb, file_size, SEEK_SET);
00506     }
00507     return 0;
00508 }
00509 
00510 #if CONFIG_SWF_MUXER
00511 AVOutputFormat ff_swf_muxer = {
00512     "swf",
00513     NULL_IF_CONFIG_SMALL("Flash format"),
00514     "application/x-shockwave-flash",
00515     "swf",
00516     sizeof(SWFContext),
00517     CODEC_ID_MP3,
00518     CODEC_ID_FLV1,
00519     swf_write_header,
00520     swf_write_packet,
00521     swf_write_trailer,
00522 };
00523 #endif
00524 #if CONFIG_AVM2_MUXER
00525 AVOutputFormat ff_avm2_muxer = {
00526     "avm2",
00527     NULL_IF_CONFIG_SMALL("Flash 9 (AVM2) format"),
00528     "application/x-shockwave-flash",
00529     NULL,
00530     sizeof(SWFContext),
00531     CODEC_ID_MP3,
00532     CODEC_ID_FLV1,
00533     swf_write_header,
00534     swf_write_packet,
00535     swf_write_trailer,
00536 };
00537 #endif