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/bitstream.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     ByteIOContext *pb = s->pb;
00031 
00032     swf->tag_pos = url_ftell(pb);
00033     swf->tag = tag;
00034     /* reserve some room for the tag */
00035     if (tag & TAG_LONG) {
00036         put_le16(pb, 0);
00037         put_le32(pb, 0);
00038     } else {
00039         put_le16(pb, 0);
00040     }
00041 }
00042 
00043 static void put_swf_end_tag(AVFormatContext *s)
00044 {
00045     SWFContext *swf = s->priv_data;
00046     ByteIOContext *pb = s->pb;
00047     int64_t pos;
00048     int tag_len, tag;
00049 
00050     pos = url_ftell(pb);
00051     tag_len = pos - swf->tag_pos - 2;
00052     tag = swf->tag;
00053     url_fseek(pb, swf->tag_pos, SEEK_SET);
00054     if (tag & TAG_LONG) {
00055         tag &= ~TAG_LONG;
00056         put_le16(pb, (tag << 6) | 0x3f);
00057         put_le32(pb, tag_len - 4);
00058     } else {
00059         assert(tag_len < 0x3f);
00060         put_le16(pb, (tag << 6) | tag_len);
00061     }
00062     url_fseek(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(ByteIOContext *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     put_buffer(pb, buf, pbBufPtr(&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(ByteIOContext *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     put_buffer(pb, buf, pbBufPtr(&p) - p.buf);
00171 }
00172 
00173 static int swf_write_header(AVFormatContext *s)
00174 {
00175     SWFContext *swf = s->priv_data;
00176     ByteIOContext *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 == CODEC_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                 av_fifo_init(&swf->audio_fifo, AUDIO_FIFO_SIZE);
00196             } else {
00197                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports MP3\n");
00198                 return -1;
00199             }
00200         } else {
00201             if (enc->codec_id == CODEC_ID_VP6F ||
00202                 enc->codec_id == CODEC_ID_FLV1 ||
00203                 enc->codec_id == CODEC_ID_MJPEG) {
00204                 swf->video_enc = enc;
00205             } else {
00206                 av_log(s, AV_LOG_ERROR, "SWF muxer only supports VP6, FLV1 and MJPEG\n");
00207                 return -1;
00208             }
00209         }
00210     }
00211 
00212     if (!swf->video_enc) {
00213         /* currently, cannot work correctly if audio only */
00214         width = 320;
00215         height = 200;
00216         rate = 10;
00217         rate_base= 1;
00218     } else {
00219         width = swf->video_enc->width;
00220         height = swf->video_enc->height;
00221         rate = swf->video_enc->time_base.den;
00222         rate_base = swf->video_enc->time_base.num;
00223     }
00224 
00225     if (!swf->audio_enc)
00226         swf->samples_per_frame = (44100. * rate_base) / rate;
00227     else
00228         swf->samples_per_frame = (swf->audio_enc->sample_rate * rate_base) / rate;
00229 
00230     put_tag(pb, "FWS");
00231 
00232     if (!strcmp("avm2", s->oformat->name))
00233         version = 9;
00234     else if (swf->video_enc && swf->video_enc->codec_id == CODEC_ID_VP6F)
00235         version = 8; /* version 8 and above support VP6 codec */
00236     else if (swf->video_enc && swf->video_enc->codec_id == CODEC_ID_FLV1)
00237         version = 6; /* version 6 and above support FLV1 codec */
00238     else
00239         version = 4; /* version 4 for mpeg audio support */
00240     put_byte(pb, version);
00241 
00242     put_le32(pb, DUMMY_FILE_SIZE); /* dummy size
00243                                       (will be patched if not streamed) */
00244 
00245     put_swf_rect(pb, 0, width * 20, 0, height * 20);
00246     put_le16(pb, (rate * 256) / rate_base); /* frame rate */
00247     swf->duration_pos = url_ftell(pb);
00248     put_le16(pb, (uint16_t)(DUMMY_DURATION * (int64_t)rate / rate_base)); /* frame count */
00249 
00250     /* avm2/swf v9 (also v8?) files require a file attribute tag */
00251     if (version == 9) {
00252         put_swf_tag(s, TAG_FILEATTRIBUTES);
00253         put_le32(pb, 1<<3); /* set ActionScript v3/AVM2 flag */
00254         put_swf_end_tag(s);
00255     }
00256 
00257     /* define a shape with the jpeg inside */
00258     if (swf->video_enc && swf->video_enc->codec_id == CODEC_ID_MJPEG) {
00259         put_swf_tag(s, TAG_DEFINESHAPE);
00260 
00261         put_le16(pb, SHAPE_ID); /* ID of shape */
00262         /* bounding rectangle */
00263         put_swf_rect(pb, 0, width, 0, height);
00264         /* style info */
00265         put_byte(pb, 1); /* one fill style */
00266         put_byte(pb, 0x41); /* clipped bitmap fill */
00267         put_le16(pb, BITMAP_ID); /* bitmap ID */
00268         /* position of the bitmap */
00269         put_swf_matrix(pb, (int)(1.0 * (1 << FRAC_BITS)), 0,
00270                        0, (int)(1.0 * (1 << FRAC_BITS)), 0, 0);
00271         put_byte(pb, 0); /* no line style */
00272 
00273         /* shape drawing */
00274         init_put_bits(&p, buf1, sizeof(buf1));
00275         put_bits(&p, 4, 1); /* one fill bit */
00276         put_bits(&p, 4, 0); /* zero line bit */
00277 
00278         put_bits(&p, 1, 0); /* not an edge */
00279         put_bits(&p, 5, FLAG_MOVETO | FLAG_SETFILL0);
00280         put_bits(&p, 5, 1); /* nbits */
00281         put_bits(&p, 1, 0); /* X */
00282         put_bits(&p, 1, 0); /* Y */
00283         put_bits(&p, 1, 1); /* set fill style 1 */
00284 
00285         /* draw the rectangle ! */
00286         put_swf_line_edge(&p, width, 0);
00287         put_swf_line_edge(&p, 0, height);
00288         put_swf_line_edge(&p, -width, 0);
00289         put_swf_line_edge(&p, 0, -height);
00290 
00291         /* end of shape */
00292         put_bits(&p, 1, 0); /* not an edge */
00293         put_bits(&p, 5, 0);
00294 
00295         flush_put_bits(&p);
00296         put_buffer(pb, buf1, pbBufPtr(&p) - p.buf);
00297 
00298         put_swf_end_tag(s);
00299     }
00300 
00301     if (swf->audio_enc && swf->audio_enc->codec_id == CODEC_ID_MP3) {
00302         int v = 0;
00303 
00304         /* start sound */
00305         put_swf_tag(s, TAG_STREAMHEAD2);
00306         switch(swf->audio_enc->sample_rate) {
00307         case 11025: v |= 1 << 2; break;
00308         case 22050: v |= 2 << 2; break;
00309         case 44100: v |= 3 << 2; break;
00310         default:
00311             /* not supported */
00312             av_log(s, AV_LOG_ERROR, "swf does not support that sample rate, choose from (44100, 22050, 11025).\n");
00313             return -1;
00314         }
00315         v |= 0x02; /* 16 bit playback */
00316         if (swf->audio_enc->channels == 2)
00317             v |= 0x01; /* stereo playback */
00318         put_byte(s->pb, v);
00319         v |= 0x20; /* mp3 compressed */
00320         put_byte(s->pb, v);
00321         put_le16(s->pb, swf->samples_per_frame);  /* avg samples per frame */
00322         put_le16(s->pb, 0);
00323 
00324         put_swf_end_tag(s);
00325     }
00326 
00327     put_flush_packet(s->pb);
00328     return 0;
00329 }
00330 
00331 static int swf_write_video(AVFormatContext *s,
00332                            AVCodecContext *enc, const uint8_t *buf, int size)
00333 {
00334     SWFContext *swf = s->priv_data;
00335     ByteIOContext *pb = s->pb;
00336 
00337     /* Flash Player limit */
00338     if (swf->swf_frame_number == 16000)
00339         av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
00340 
00341     if (enc->codec_id == CODEC_ID_VP6F ||
00342         enc->codec_id == CODEC_ID_FLV1) {
00343         if (swf->video_frame_number == 0) {
00344             /* create a new video object */
00345             put_swf_tag(s, TAG_VIDEOSTREAM);
00346             put_le16(pb, VIDEO_ID);
00347             swf->vframes_pos = url_ftell(pb);
00348             put_le16(pb, 15000); /* hard flash player limit */
00349             put_le16(pb, enc->width);
00350             put_le16(pb, enc->height);
00351             put_byte(pb, 0);
00352             put_byte(pb,codec_get_tag(swf_codec_tags,enc->codec_id));
00353             put_swf_end_tag(s);
00354 
00355             /* place the video object for the first time */
00356             put_swf_tag(s, TAG_PLACEOBJECT2);
00357             put_byte(pb, 0x36);
00358             put_le16(pb, 1);
00359             put_le16(pb, VIDEO_ID);
00360             put_swf_matrix(pb, 1 << FRAC_BITS, 0, 0, 1 << FRAC_BITS, 0, 0);
00361             put_le16(pb, swf->video_frame_number);
00362             put_tag(pb, "video");
00363             put_byte(pb, 0x00);
00364             put_swf_end_tag(s);
00365         } else {
00366             /* mark the character for update */
00367             put_swf_tag(s, TAG_PLACEOBJECT2);
00368             put_byte(pb, 0x11);
00369             put_le16(pb, 1);
00370             put_le16(pb, swf->video_frame_number);
00371             put_swf_end_tag(s);
00372         }
00373 
00374         /* set video frame data */
00375         put_swf_tag(s, TAG_VIDEOFRAME | TAG_LONG);
00376         put_le16(pb, VIDEO_ID);
00377         put_le16(pb, swf->video_frame_number++);
00378         put_buffer(pb, buf, size);
00379         put_swf_end_tag(s);
00380     } else if (enc->codec_id == CODEC_ID_MJPEG) {
00381         if (swf->swf_frame_number > 0) {
00382             /* remove the shape */
00383             put_swf_tag(s, TAG_REMOVEOBJECT);
00384             put_le16(pb, SHAPE_ID); /* shape ID */
00385             put_le16(pb, 1); /* depth */
00386             put_swf_end_tag(s);
00387 
00388             /* free the bitmap */
00389             put_swf_tag(s, TAG_FREECHARACTER);
00390             put_le16(pb, BITMAP_ID);
00391             put_swf_end_tag(s);
00392         }
00393 
00394         put_swf_tag(s, TAG_JPEG2 | TAG_LONG);
00395 
00396         put_le16(pb, BITMAP_ID); /* ID of the image */
00397 
00398         /* a dummy jpeg header seems to be required */
00399         put_be32(pb, 0xffd8ffd9);
00400         /* write the jpeg image */
00401         put_buffer(pb, buf, size);
00402 
00403         put_swf_end_tag(s);
00404 
00405         /* draw the shape */
00406 
00407         put_swf_tag(s, TAG_PLACEOBJECT);
00408         put_le16(pb, SHAPE_ID); /* shape ID */
00409         put_le16(pb, 1); /* depth */
00410         put_swf_matrix(pb, 20 << FRAC_BITS, 0, 0, 20 << FRAC_BITS, 0, 0);
00411         put_swf_end_tag(s);
00412     }
00413 
00414     swf->swf_frame_number++;
00415 
00416     /* streaming sound always should be placed just before showframe tags */
00417     if (swf->audio_enc && av_fifo_size(&swf->audio_fifo)) {
00418         int frame_size = av_fifo_size(&swf->audio_fifo);
00419         put_swf_tag(s, TAG_STREAMBLOCK | TAG_LONG);
00420         put_le16(pb, swf->sound_samples);
00421         put_le16(pb, 0); // seek samples
00422         av_fifo_generic_read(&swf->audio_fifo, frame_size, &put_buffer, pb);
00423         put_swf_end_tag(s);
00424 
00425         /* update FIFO */
00426         swf->sound_samples = 0;
00427     }
00428 
00429     /* output the frame */
00430     put_swf_tag(s, TAG_SHOWFRAME);
00431     put_swf_end_tag(s);
00432 
00433     put_flush_packet(s->pb);
00434 
00435     return 0;
00436 }
00437 
00438 static int swf_write_audio(AVFormatContext *s,
00439                            AVCodecContext *enc, uint8_t *buf, int size)
00440 {
00441     SWFContext *swf = s->priv_data;
00442 
00443     /* Flash Player limit */
00444     if (swf->swf_frame_number == 16000)
00445         av_log(enc, AV_LOG_INFO, "warning: Flash Player limit of 16000 frames reached\n");
00446 
00447     if (av_fifo_size(&swf->audio_fifo) + size > AUDIO_FIFO_SIZE) {
00448         av_log(s, AV_LOG_ERROR, "audio fifo too small to mux audio essence\n");
00449         return -1;
00450     }
00451 
00452     av_fifo_generic_write(&swf->audio_fifo, buf, size, NULL);
00453     swf->sound_samples += enc->frame_size;
00454 
00455     /* if audio only stream make sure we add swf frames */
00456     if (!swf->video_enc)
00457         swf_write_video(s, enc, 0, 0);
00458 
00459     return 0;
00460 }
00461 
00462 static int swf_write_packet(AVFormatContext *s, AVPacket *pkt)
00463 {
00464     AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
00465     if (codec->codec_type == CODEC_TYPE_AUDIO)
00466         return swf_write_audio(s, codec, pkt->data, pkt->size);
00467     else
00468         return swf_write_video(s, codec, pkt->data, pkt->size);
00469 }
00470 
00471 static int swf_write_trailer(AVFormatContext *s)
00472 {
00473     SWFContext *swf = s->priv_data;
00474     ByteIOContext *pb = s->pb;
00475     AVCodecContext *enc, *video_enc;
00476     int file_size, i;
00477 
00478     video_enc = NULL;
00479     for(i=0;i<s->nb_streams;i++) {
00480         enc = s->streams[i]->codec;
00481         if (enc->codec_type == CODEC_TYPE_VIDEO)
00482             video_enc = enc;
00483         else
00484             av_fifo_free(&swf->audio_fifo);
00485     }
00486 
00487     put_swf_tag(s, TAG_END);
00488     put_swf_end_tag(s);
00489 
00490     put_flush_packet(s->pb);
00491 
00492     /* patch file size and number of frames if not streamed */
00493     if (!url_is_streamed(s->pb) && video_enc) {
00494         file_size = url_ftell(pb);
00495         url_fseek(pb, 4, SEEK_SET);
00496         put_le32(pb, file_size);
00497         url_fseek(pb, swf->duration_pos, SEEK_SET);
00498         put_le16(pb, swf->video_frame_number);
00499         if (swf->vframes_pos) {
00500         url_fseek(pb, swf->vframes_pos, SEEK_SET);
00501         put_le16(pb, swf->video_frame_number);
00502         }
00503         url_fseek(pb, file_size, SEEK_SET);
00504     }
00505     return 0;
00506 }
00507 
00508 #if CONFIG_SWF_MUXER
00509 AVOutputFormat swf_muxer = {
00510     "swf",
00511     NULL_IF_CONFIG_SMALL("Flash format"),
00512     "application/x-shockwave-flash",
00513     "swf",
00514     sizeof(SWFContext),
00515     CODEC_ID_MP3,
00516     CODEC_ID_FLV1,
00517     swf_write_header,
00518     swf_write_packet,
00519     swf_write_trailer,
00520 };
00521 #endif
00522 #if CONFIG_AVM2_MUXER
00523 AVOutputFormat avm2_muxer = {
00524     "avm2",
00525     NULL_IF_CONFIG_SMALL("Flash 9 (AVM2) format"),
00526     "application/x-shockwave-flash",
00527     NULL,
00528     sizeof(SWFContext),
00529     CODEC_ID_MP3,
00530     CODEC_ID_FLV1,
00531     swf_write_header,
00532     swf_write_packet,
00533     swf_write_trailer,
00534 };
00535 #endif