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 "libavutil/avassert.h"
00025 #include "avformat.h"
00026 #include "swf.h"
00027 
00028 static void put_swf_tag(AVFormatContext *s, int tag)
00029 {
00030     SWFContext *swf = s->priv_data;
00031     AVIOContext *pb = s->pb;
00032 
00033     swf->tag_pos = avio_tell(pb);
00034     swf->tag = tag;
00035     /* reserve some room for the tag */
00036     if (tag & TAG_LONG) {
00037         avio_wl16(pb, 0);
00038         avio_wl32(pb, 0);
00039     } else {
00040         avio_wl16(pb, 0);
00041     }
00042 }
00043 
00044 static void put_swf_end_tag(AVFormatContext *s)
00045 {
00046     SWFContext *swf = s->priv_data;
00047     AVIOContext *pb = s->pb;
00048     int64_t pos;
00049     int tag_len, tag;
00050 
00051     pos = avio_tell(pb);
00052     tag_len = pos - swf->tag_pos - 2;
00053     tag = swf->tag;
00054     avio_seek(pb, swf->tag_pos, SEEK_SET);
00055     if (tag & TAG_LONG) {
00056         tag &= ~TAG_LONG;
00057         avio_wl16(pb, (tag << 6) | 0x3f);
00058         avio_wl32(pb, tag_len - 4);
00059     } else {
00060         av_assert0(tag_len < 0x3f);
00061         avio_wl16(pb, (tag << 6) | tag_len);
00062     }
00063     avio_seek(pb, pos, SEEK_SET);
00064 }
00065 
00066 static inline void max_nbits(int *nbits_ptr, int val)
00067 {
00068     int n;
00069 
00070     if (val == 0)
00071         return;
00072     val = abs(val);
00073     n = 1;
00074     while (val != 0) {
00075         n++;
00076         val >>= 1;
00077     }
00078     if (n > *nbits_ptr)
00079         *nbits_ptr = n;
00080 }
00081 
00082 static void put_swf_rect(AVIOContext *pb,
00083                          int xmin, int xmax, int ymin, int ymax)
00084 {
00085     PutBitContext p;
00086     uint8_t buf[256];
00087     int nbits, mask;
00088 
00089     init_put_bits(&p, buf, sizeof(buf));
00090 
00091     nbits = 0;
00092     max_nbits(&nbits, xmin);
00093     max_nbits(&nbits, xmax);
00094     max_nbits(&nbits, ymin);
00095     max_nbits(&nbits, ymax);
00096     mask = (1 << nbits) - 1;
00097 
00098     /* rectangle info */
00099     put_bits(&p, 5, nbits);
00100     put_bits(&p, nbits, xmin & mask);
00101     put_bits(&p, nbits, xmax & mask);
00102     put_bits(&p, nbits, ymin & mask);
00103     put_bits(&p, nbits, ymax & mask);
00104 
00105     flush_put_bits(&p);
00106     avio_write(pb, buf, put_bits_ptr(&p) - p.buf);
00107 }
00108 
00109 static void put_swf_line_edge(PutBitContext *pb, int dx, int dy)
00110 {
00111     int nbits, mask;
00112 
00113     put_bits(pb, 1, 1); /* edge */
00114     put_bits(pb, 1, 1); /* line select */
00115     nbits = 2;
00116     max_nbits(&nbits, dx);
00117     max_nbits(&nbits, dy);
00118 
00119     mask = (1 << nbits) - 1;
00120     put_bits(pb, 4, nbits - 2); /* 16 bits precision */
00121     if (dx == 0) {
00122         put_bits(pb, 1, 0);
00123         put_bits(pb, 1, 1);
00124         put_bits(pb, nbits, dy & mask);
00125     } else if (dy == 0) {
00126         put_bits(pb, 1, 0);
00127         put_bits(pb, 1, 0);
00128         put_bits(pb, nbits, dx & mask);
00129     } else {
00130         put_bits(pb, 1, 1);
00131         put_bits(pb, nbits, dx & mask);
00132         put_bits(pb, nbits, dy & mask);
00133     }
00134 }
00135 
00136 #define FRAC_BITS 16
00137 
00138 static void put_swf_matrix(AVIOContext *pb,
00139                            int a, int b, int c, int d, int tx, int ty)
00140 {
00141     PutBitContext p;
00142     uint8_t buf[256];
00143     int nbits;
00144 
00145     init_put_bits(&p, buf, sizeof(buf));
00146 
00147     put_bits(&p, 1, 1); /* a, d present */
00148     nbits = 1;
00149     max_nbits(&nbits, a);
00150     max_nbits(&nbits, d);
00151     put_bits(&p, 5, nbits); /* nb bits */
00152     put_bits(&p, nbits, a);
00153     put_bits(&p, nbits, d);
00154 
00155     put_bits(&p, 1, 1); /* b, c present */
00156     nbits = 1;
00157     max_nbits(&nbits, c);
00158     max_nbits(&nbits, b);
00159     put_bits(&p, 5, nbits); /* nb bits */
00160     put_bits(&p, nbits, c);
00161     put_bits(&p, nbits, b);
00162 
00163     nbits = 1;
00164     max_nbits(&nbits, tx);
00165     max_nbits(&nbits, ty);
00166     put_bits(&p, 5, nbits); /* nb bits */
00167     put_bits(&p, nbits, tx);
00168     put_bits(&p, nbits, ty);
00169 
00170     flush_put_bits(&p);
00171     avio_write(pb, buf, put_bits_ptr(&p) - p.buf);
00172 }
00173 
00174 static int swf_write_header(AVFormatContext *s)
00175 {
00176     SWFContext *swf = s->priv_data;
00177     AVIOContext *pb = s->pb;
00178     PutBitContext p;
00179     uint8_t buf1[256];
00180     int i, width, height, rate, rate_base;
00181     int version;
00182 
00183     swf->sound_samples = 0;
00184     swf->swf_frame_number = 0;
00185     swf->video_frame_number = 0;
00186 
00187     for(i=0;i<s->nb_streams;i++) {
00188         AVCodecContext *enc = s->streams[i]->codec;
00189         if (enc->codec_type == AVMEDIA_TYPE_AUDIO) {
00190             if (enc->codec_id == AV_CODEC_ID_MP3) {
00191                 swf->audio_enc = enc;
00192                 swf->audio_fifo= av_fifo_alloc(AUDIO_FIFO_SIZE);
00193                 if (!swf->audio_fifo)
00194                     return AVERROR(ENOMEM);
00195             } else {
00196                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports MP3\n");
00197                 return -1;
00198             }
00199         } else {
00200             if (enc->codec_id == AV_CODEC_ID_VP6F ||
00201                 enc->codec_id == AV_CODEC_ID_FLV1 ||
00202                 enc->codec_id == AV_CODEC_ID_MJPEG) {
00203                 swf->video_enc = enc;
00204             } else {
00205                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports VP6, FLV1 and MJPEG\n");
00206                 return -1;
00207             }
00208         }
00209     }
00210 
00211     if (!swf->video_enc) {
00212         /* currently, cannot work correctly if audio only */
00213         width = 320;
00214         height = 200;
00215         rate = 10;
00216         rate_base= 1;
00217     } else {
00218         width = swf->video_enc->width;
00219         height = swf->video_enc->height;
00220         rate = swf->video_enc->time_base.den;
00221         rate_base = swf->video_enc->time_base.num;
00222     }
00223 
00224     if (!swf->audio_enc)
00225         swf->samples_per_frame = (44100. * rate_base) / rate;
00226     else
00227         swf->samples_per_frame = (swf->audio_enc->sample_rate * rate_base) / rate;
00228 
00229     avio_write(pb, "FWS", 3);
00230 
00231     if (!strcmp("avm2", s->oformat->name))
00232         version = 9;
00233     else if (swf->video_enc && swf->video_enc->codec_id == AV_CODEC_ID_VP6F)
00234         version = 8; /* version 8 and above support VP6 codec */
00235     else if (swf->video_enc && swf->video_enc->codec_id == AV_CODEC_ID_FLV1)
00236         version = 6; /* version 6 and above support FLV1 codec */
00237     else
00238         version = 4; /* version 4 for mpeg audio support */
00239     avio_w8(pb, version);
00240 
00241     avio_wl32(pb, DUMMY_FILE_SIZE); /* dummy size
00242                                       (will be patched if not streamed) */
00243 
00244     put_swf_rect(pb, 0, width * 20, 0, height * 20);
00245     avio_wl16(pb, (rate * 256) / rate_base); /* frame rate */
00246     swf->duration_pos = avio_tell(pb);
00247     avio_wl16(pb, (uint16_t)(DUMMY_DURATION * (int64_t)rate / rate_base)); /* frame count */
00248 
00249     /* avm2/swf v9 (also v8?) files require a file attribute tag */
00250     if (version == 9) {
00251         put_swf_tag(s, TAG_FILEATTRIBUTES);
00252         avio_wl32(pb, 1<<3); /* set ActionScript v3/AVM2 flag */
00253         put_swf_end_tag(s);
00254     }
00255 
00256     /* define a shape with the jpeg inside */
00257     if (swf->video_enc && swf->video_enc->codec_id == AV_CODEC_ID_MJPEG) {
00258         put_swf_tag(s, TAG_DEFINESHAPE);
00259 
00260         avio_wl16(pb, SHAPE_ID); /* ID of shape */
00261         /* bounding rectangle */
00262         put_swf_rect(pb, 0, width, 0, height);
00263         /* style info */
00264         avio_w8(pb, 1); /* one fill style */
00265         avio_w8(pb, 0x41); /* clipped bitmap fill */
00266         avio_wl16(pb, BITMAP_ID); /* bitmap ID */
00267         /* position of the bitmap */
00268         put_swf_matrix(pb, (int)(1.0 * (1 << FRAC_BITS)), 0,
00269                        0, (int)(1.0 * (1 << FRAC_BITS)), 0, 0);
00270         avio_w8(pb, 0); /* no line style */
00271 
00272         /* shape drawing */
00273         init_put_bits(&p, buf1, sizeof(buf1));
00274         put_bits(&p, 4, 1); /* one fill bit */
00275         put_bits(&p, 4, 0); /* zero line bit */
00276 
00277         put_bits(&p, 1, 0); /* not an edge */
00278         put_bits(&p, 5, FLAG_MOVETO | FLAG_SETFILL0);
00279         put_bits(&p, 5, 1); /* nbits */
00280         put_bits(&p, 1, 0); /* X */
00281         put_bits(&p, 1, 0); /* Y */
00282         put_bits(&p, 1, 1); /* set fill style 1 */
00283 
00284         /* draw the rectangle ! */
00285         put_swf_line_edge(&p, width, 0);
00286         put_swf_line_edge(&p, 0, height);
00287         put_swf_line_edge(&p, -width, 0);
00288         put_swf_line_edge(&p, 0, -height);
00289 
00290         /* end of shape */
00291         put_bits(&p, 1, 0); /* not an edge */
00292         put_bits(&p, 5, 0);
00293 
00294         flush_put_bits(&p);
00295         avio_write(pb, buf1, put_bits_ptr(&p) - p.buf);
00296 
00297         put_swf_end_tag(s);
00298     }
00299 
00300     if (swf->audio_enc && swf->audio_enc->codec_id == AV_CODEC_ID_MP3) {
00301         int v = 0;
00302 
00303         /* start sound */
00304         put_swf_tag(s, TAG_STREAMHEAD2);
00305         switch(swf->audio_enc->sample_rate) {
00306         case 11025: v |= 1 << 2; break;
00307         case 22050: v |= 2 << 2; break;
00308         case 44100: v |= 3 << 2; break;
00309         default:
00310             /* not supported */
00311             av_log(s, AV_LOG_ERROR, "swf does not support that sample rate, choose from (44100, 22050, 11025).\n");
00312             return -1;
00313         }
00314         v |= 0x02; /* 16 bit playback */
00315         if (swf->audio_enc->channels == 2)
00316             v |= 0x01; /* stereo playback */
00317         avio_w8(s->pb, v);
00318         v |= 0x20; /* mp3 compressed */
00319         avio_w8(s->pb, v);
00320         avio_wl16(s->pb, swf->samples_per_frame);  /* avg samples per frame */
00321         avio_wl16(s->pb, 0);
00322 
00323         put_swf_end_tag(s);
00324     }
00325 
00326     avio_flush(s->pb);
00327     return 0;
00328 }
00329 
00330 static int swf_write_video(AVFormatContext *s,
00331                            AVCodecContext *enc, const uint8_t *buf, int size)
00332 {
00333     SWFContext *swf = s->priv_data;
00334     AVIOContext *pb = s->pb;
00335 
00336     /* Flash Player limit */
00337     if (swf->swf_frame_number == 16000)
00338         av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
00339 
00340     if (enc->codec_id == AV_CODEC_ID_VP6F ||
00341         enc->codec_id == AV_CODEC_ID_FLV1) {
00342         if (swf->video_frame_number == 0) {
00343             /* create a new video object */
00344             put_swf_tag(s, TAG_VIDEOSTREAM);
00345             avio_wl16(pb, VIDEO_ID);
00346             swf->vframes_pos = avio_tell(pb);
00347             avio_wl16(pb, 15000); /* hard flash player limit */
00348             avio_wl16(pb, enc->width);
00349             avio_wl16(pb, enc->height);
00350             avio_w8(pb, 0);
00351             avio_w8(pb,ff_codec_get_tag(ff_swf_codec_tags, enc->codec_id));
00352             put_swf_end_tag(s);
00353 
00354             /* place the video object for the first time */
00355             put_swf_tag(s, TAG_PLACEOBJECT2);
00356             avio_w8(pb, 0x36);
00357             avio_wl16(pb, 1);
00358             avio_wl16(pb, VIDEO_ID);
00359             put_swf_matrix(pb, 1 << FRAC_BITS, 0, 0, 1 << FRAC_BITS, 0, 0);
00360             avio_wl16(pb, swf->video_frame_number);
00361             avio_write(pb, "video", 5);
00362             avio_w8(pb, 0x00);
00363             put_swf_end_tag(s);
00364         } else {
00365             /* mark the character for update */
00366             put_swf_tag(s, TAG_PLACEOBJECT2);
00367             avio_w8(pb, 0x11);
00368             avio_wl16(pb, 1);
00369             avio_wl16(pb, swf->video_frame_number);
00370             put_swf_end_tag(s);
00371         }
00372 
00373         /* set video frame data */
00374         put_swf_tag(s, TAG_VIDEOFRAME | TAG_LONG);
00375         avio_wl16(pb, VIDEO_ID);
00376         avio_wl16(pb, swf->video_frame_number++);
00377         avio_write(pb, buf, size);
00378         put_swf_end_tag(s);
00379     } else if (enc->codec_id == AV_CODEC_ID_MJPEG) {
00380         if (swf->swf_frame_number > 0) {
00381             /* remove the shape */
00382             put_swf_tag(s, TAG_REMOVEOBJECT);
00383             avio_wl16(pb, SHAPE_ID); /* shape ID */
00384             avio_wl16(pb, 1); /* depth */
00385             put_swf_end_tag(s);
00386 
00387             /* free the bitmap */
00388             put_swf_tag(s, TAG_FREECHARACTER);
00389             avio_wl16(pb, BITMAP_ID);
00390             put_swf_end_tag(s);
00391         }
00392 
00393         put_swf_tag(s, TAG_JPEG2 | TAG_LONG);
00394 
00395         avio_wl16(pb, BITMAP_ID); /* ID of the image */
00396 
00397         /* a dummy jpeg header seems to be required */
00398         avio_wb32(pb, 0xffd8ffd9);
00399         /* write the jpeg image */
00400         avio_write(pb, buf, size);
00401 
00402         put_swf_end_tag(s);
00403 
00404         /* draw the shape */
00405 
00406         put_swf_tag(s, TAG_PLACEOBJECT);
00407         avio_wl16(pb, SHAPE_ID); /* shape ID */
00408         avio_wl16(pb, 1); /* depth */
00409         put_swf_matrix(pb, 20 << FRAC_BITS, 0, 0, 20 << FRAC_BITS, 0, 0);
00410         put_swf_end_tag(s);
00411     }
00412 
00413     swf->swf_frame_number++;
00414 
00415     /* streaming sound always should be placed just before showframe tags */
00416     if (swf->audio_enc && av_fifo_size(swf->audio_fifo)) {
00417         int frame_size = av_fifo_size(swf->audio_fifo);
00418         put_swf_tag(s, TAG_STREAMBLOCK | TAG_LONG);
00419         avio_wl16(pb, swf->sound_samples);
00420         avio_wl16(pb, 0); // seek samples
00421         av_fifo_generic_read(swf->audio_fifo, pb, frame_size, (void*)avio_write);
00422         put_swf_end_tag(s);
00423 
00424         /* update FIFO */
00425         swf->sound_samples = 0;
00426     }
00427 
00428     /* output the frame */
00429     put_swf_tag(s, TAG_SHOWFRAME);
00430     put_swf_end_tag(s);
00431 
00432     avio_flush(s->pb);
00433 
00434     return 0;
00435 }
00436 
00437 static int swf_write_audio(AVFormatContext *s,
00438                            AVCodecContext *enc, uint8_t *buf, int size)
00439 {
00440     SWFContext *swf = s->priv_data;
00441 
00442     /* Flash Player limit */
00443     if (swf->swf_frame_number == 16000)
00444         av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
00445 
00446     if (av_fifo_size(swf->audio_fifo) + size > AUDIO_FIFO_SIZE) {
00447         av_log(s, AV_LOG_ERROR, "audio fifo too small to mux audio essence\n");
00448         return -1;
00449     }
00450 
00451     av_fifo_generic_write(swf->audio_fifo, buf, size, NULL);
00452     swf->sound_samples += av_get_audio_frame_duration(enc, size);
00453 
00454     /* if audio only stream make sure we add swf frames */
00455     if (!swf->video_enc)
00456         swf_write_video(s, enc, 0, 0);
00457 
00458     return 0;
00459 }
00460 
00461 static int swf_write_packet(AVFormatContext *s, AVPacket *pkt)
00462 {
00463     AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
00464     if (codec->codec_type == AVMEDIA_TYPE_AUDIO)
00465         return swf_write_audio(s, codec, pkt->data, pkt->size);
00466     else
00467         return swf_write_video(s, codec, pkt->data, pkt->size);
00468 }
00469 
00470 static int swf_write_trailer(AVFormatContext *s)
00471 {
00472     SWFContext *swf = s->priv_data;
00473     AVIOContext *pb = s->pb;
00474     AVCodecContext *enc, *video_enc;
00475     int file_size, i;
00476 
00477     video_enc = NULL;
00478     for(i=0;i<s->nb_streams;i++) {
00479         enc = s->streams[i]->codec;
00480         if (enc->codec_type == AVMEDIA_TYPE_VIDEO)
00481             video_enc = enc;
00482         else
00483             av_fifo_free(swf->audio_fifo);
00484     }
00485 
00486     put_swf_tag(s, TAG_END);
00487     put_swf_end_tag(s);
00488 
00489     /* patch file size and number of frames if not streamed */
00490     if (s->pb->seekable && video_enc) {
00491         file_size = avio_tell(pb);
00492         avio_seek(pb, 4, SEEK_SET);
00493         avio_wl32(pb, file_size);
00494         avio_seek(pb, swf->duration_pos, SEEK_SET);
00495         avio_wl16(pb, swf->video_frame_number);
00496         if (swf->vframes_pos) {
00497         avio_seek(pb, swf->vframes_pos, SEEK_SET);
00498         avio_wl16(pb, swf->video_frame_number);
00499         }
00500         avio_seek(pb, file_size, SEEK_SET);
00501     }
00502     return 0;
00503 }
00504 
00505 #if CONFIG_SWF_MUXER
00506 AVOutputFormat ff_swf_muxer = {
00507     .name              = "swf",
00508     .long_name         = NULL_IF_CONFIG_SMALL("SWF (ShockWave Flash)"),
00509     .mime_type         = "application/x-shockwave-flash",
00510     .extensions        = "swf",
00511     .priv_data_size    = sizeof(SWFContext),
00512     .audio_codec       = AV_CODEC_ID_MP3,
00513     .video_codec       = AV_CODEC_ID_FLV1,
00514     .write_header      = swf_write_header,
00515     .write_packet      = swf_write_packet,
00516     .write_trailer     = swf_write_trailer,
00517     .flags             = AVFMT_TS_NONSTRICT,
00518 };
00519 #endif
00520 #if CONFIG_AVM2_MUXER
00521 AVOutputFormat ff_avm2_muxer = {
00522     .name              = "avm2",
00523     .long_name         = NULL_IF_CONFIG_SMALL("SWF (ShockWave Flash) (AVM2)"),
00524     .mime_type         = "application/x-shockwave-flash",
00525     .priv_data_size    = sizeof(SWFContext),
00526     .audio_codec       = AV_CODEC_ID_MP3,
00527     .video_codec       = AV_CODEC_ID_FLV1,
00528     .write_header      = swf_write_header,
00529     .write_packet      = swf_write_packet,
00530     .write_trailer     = swf_write_trailer,
00531     .flags             = AVFMT_TS_NONSTRICT,
00532 };
00533 #endif