FFmpeg: libavformat/rmenc.c Source File

00001 /*
00002  * "Real" compatible muxer.
00003  * Copyright (c) 2000, 2001 Fabrice Bellard
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 #include "avformat.h"
00022 #include "avio_internal.h"
00023 #include "rm.h"
00024 #include "libavutil/dict.h"
00025 
00026 typedef struct {
00027     int nb_packets;
00028     int packet_total_size;
00029     int packet_max_size;
00030     /* codec related output */
00031     int bit_rate;
00032     float frame_rate;
00033     int nb_frames;    /* current frame number */
00034     int total_frames; /* total number of frames */
00035     int num;
00036     AVCodecContext *enc;
00037 } StreamInfo;
00038 
00039 typedef struct {
00040     StreamInfo streams[2];
00041     StreamInfo *audio_stream, *video_stream;
00042     int data_pos; /* position of the data after the header */
00043 } RMMuxContext;
00044 
00045 /* in ms */
00046 #define BUFFER_DURATION 0
00047 
00048 
00049 static void put_str(AVIOContext *s, const char *tag)
00050 {
00051     avio_wb16(s,strlen(tag));
00052     while (*tag) {
00053         avio_w8(s, *tag++);
00054     }
00055 }
00056 
00057 static void put_str8(AVIOContext *s, const char *tag)
00058 {
00059     avio_w8(s, strlen(tag));
00060     while (*tag) {
00061         avio_w8(s, *tag++);
00062     }
00063 }
00064 
00065 static int rv10_write_header(AVFormatContext *ctx,
00066                              int data_size, int index_pos)
00067 {
00068     RMMuxContext *rm = ctx->priv_data;
00069     AVIOContext *s = ctx->pb;
00070     StreamInfo *stream;
00071     unsigned char *data_offset_ptr, *start_ptr;
00072     const char *desc, *mimetype;
00073     int nb_packets, packet_total_size, packet_max_size, size, packet_avg_size, i;
00074     int bit_rate, v, duration, flags, data_pos;
00075     AVDictionaryEntry *tag;
00076 
00077     start_ptr = s->buf_ptr;
00078 
00079     ffio_wfourcc(s, ".RMF");
00080     avio_wb32(s,18); /* header size */
00081     avio_wb16(s,0);
00082     avio_wb32(s,0);
00083     avio_wb32(s,4 + ctx->nb_streams); /* num headers */
00084 
00085     ffio_wfourcc(s,"PROP");
00086     avio_wb32(s, 50);
00087     avio_wb16(s, 0);
00088     packet_max_size = 0;
00089     packet_total_size = 0;
00090     nb_packets = 0;
00091     bit_rate = 0;
00092     duration = 0;
00093     for(i=0;i<ctx->nb_streams;i++) {
00094         StreamInfo *stream = &rm->streams[i];
00095         bit_rate += stream->bit_rate;
00096         if (stream->packet_max_size > packet_max_size)
00097             packet_max_size = stream->packet_max_size;
00098         nb_packets += stream->nb_packets;
00099         packet_total_size += stream->packet_total_size;
00100         /* select maximum duration */
00101         v = (int) (1000.0 * (float)stream->total_frames / stream->frame_rate);
00102         if (v > duration)
00103             duration = v;
00104     }
00105     avio_wb32(s, bit_rate); /* max bit rate */
00106     avio_wb32(s, bit_rate); /* avg bit rate */
00107     avio_wb32(s, packet_max_size);        /* max packet size */
00108     if (nb_packets > 0)
00109         packet_avg_size = packet_total_size / nb_packets;
00110     else
00111         packet_avg_size = 0;
00112     avio_wb32(s, packet_avg_size);        /* avg packet size */
00113     avio_wb32(s, nb_packets);  /* num packets */
00114     avio_wb32(s, duration); /* duration */
00115     avio_wb32(s, BUFFER_DURATION);           /* preroll */
00116     avio_wb32(s, index_pos);           /* index offset */
00117     /* computation of data the data offset */
00118     data_offset_ptr = s->buf_ptr;
00119     avio_wb32(s, 0);           /* data offset : will be patched after */
00120     avio_wb16(s, ctx->nb_streams);    /* num streams */
00121     flags = 1 | 2; /* save allowed & perfect play */
00122     if (!s->seekable)
00123         flags |= 4; /* live broadcast */
00124     avio_wb16(s, flags);
00125 
00126     /* comments */
00127 
00128     ffio_wfourcc(s,"CONT");
00129     size =  4 * 2 + 10;
00130     for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) {
00131         tag = av_dict_get(ctx->metadata, ff_rm_metadata[i], NULL, 0);
00132         if(tag) size += strlen(tag->value);
00133     }
00134     avio_wb32(s,size);
00135     avio_wb16(s,0);
00136     for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) {
00137         tag = av_dict_get(ctx->metadata, ff_rm_metadata[i], NULL, 0);
00138         put_str(s, tag ? tag->value : "");
00139     }
00140 
00141     for(i=0;i<ctx->nb_streams;i++) {
00142         int codec_data_size;
00143 
00144         stream = &rm->streams[i];
00145 
00146         if (stream->enc->codec_type == AVMEDIA_TYPE_AUDIO) {
00147             desc = "The Audio Stream";
00148             mimetype = "audio/x-pn-realaudio";
00149             codec_data_size = 73;
00150         } else {
00151             desc = "The Video Stream";
00152             mimetype = "video/x-pn-realvideo";
00153             codec_data_size = 34;
00154         }
00155 
00156         ffio_wfourcc(s,"MDPR");
00157         size = 10 + 9 * 4 + strlen(desc) + strlen(mimetype) + codec_data_size;
00158         avio_wb32(s, size);
00159         avio_wb16(s, 0);
00160 
00161         avio_wb16(s, i); /* stream number */
00162         avio_wb32(s, stream->bit_rate); /* max bit rate */
00163         avio_wb32(s, stream->bit_rate); /* avg bit rate */
00164         avio_wb32(s, stream->packet_max_size);        /* max packet size */
00165         if (stream->nb_packets > 0)
00166             packet_avg_size = stream->packet_total_size /
00167                 stream->nb_packets;
00168         else
00169             packet_avg_size = 0;
00170         avio_wb32(s, packet_avg_size);        /* avg packet size */
00171         avio_wb32(s, 0);           /* start time */
00172         avio_wb32(s, BUFFER_DURATION);           /* preroll */
00173         /* duration */
00174         if (!s->seekable || !stream->total_frames)
00175             avio_wb32(s, (int)(3600 * 1000));
00176         else
00177             avio_wb32(s, (int)(stream->total_frames * 1000 / stream->frame_rate));
00178         put_str8(s, desc);
00179         put_str8(s, mimetype);
00180         avio_wb32(s, codec_data_size);
00181 
00182         if (stream->enc->codec_type == AVMEDIA_TYPE_AUDIO) {
00183             int coded_frame_size, fscode, sample_rate;
00184             sample_rate = stream->enc->sample_rate;
00185             coded_frame_size = (stream->enc->bit_rate *
00186                                 stream->enc->frame_size) / (8 * sample_rate);
00187             /* audio codec info */
00188             avio_write(s, ".ra", 3);
00189             avio_w8(s, 0xfd);
00190             avio_wb32(s, 0x00040000); /* version */
00191             ffio_wfourcc(s, ".ra4");
00192             avio_wb32(s, 0x01b53530); /* stream length */
00193             avio_wb16(s, 4); /* unknown */
00194             avio_wb32(s, 0x39); /* header size */
00195 
00196             switch(sample_rate) {
00197             case 48000:
00198             case 24000:
00199             case 12000:
00200                 fscode = 1;
00201                 break;
00202             default:
00203             case 44100:
00204             case 22050:
00205             case 11025:
00206                 fscode = 2;
00207                 break;
00208             case 32000:
00209             case 16000:
00210             case 8000:
00211                 fscode = 3;
00212             }
00213             avio_wb16(s, fscode); /* codec additional info, for AC-3, seems
00214                                      to be a frequency code */
00215             /* special hack to compensate rounding errors... */
00216             if (coded_frame_size == 557)
00217                 coded_frame_size--;
00218             avio_wb32(s, coded_frame_size); /* frame length */
00219             avio_wb32(s, 0x51540); /* unknown */
00220             avio_wb32(s, 0x249f0); /* unknown */
00221             avio_wb32(s, 0x249f0); /* unknown */
00222             avio_wb16(s, 0x01);
00223             /* frame length : seems to be very important */
00224             avio_wb16(s, coded_frame_size);
00225             avio_wb32(s, 0); /* unknown */
00226             avio_wb16(s, stream->enc->sample_rate); /* sample rate */
00227             avio_wb32(s, 0x10); /* unknown */
00228             avio_wb16(s, stream->enc->channels);
00229             put_str8(s, "Int0"); /* codec name */
00230             if (stream->enc->codec_tag) {
00231                 avio_w8(s, 4); /* tag length */
00232                 avio_wl32(s, stream->enc->codec_tag);
00233             } else {
00234                 av_log(ctx, AV_LOG_ERROR, "Invalid codec tag\n");
00235                 return -1;
00236             }
00237             avio_wb16(s, 0); /* title length */
00238             avio_wb16(s, 0); /* author length */
00239             avio_wb16(s, 0); /* copyright length */
00240             avio_w8(s, 0); /* end of header */
00241         } else {
00242             /* video codec info */
00243             avio_wb32(s,34); /* size */
00244             ffio_wfourcc(s, "VIDO");
00245             if(stream->enc->codec_id == CODEC_ID_RV10)
00246                 ffio_wfourcc(s,"RV10");
00247             else
00248                 ffio_wfourcc(s,"RV20");
00249             avio_wb16(s, stream->enc->width);
00250             avio_wb16(s, stream->enc->height);
00251             avio_wb16(s, (int) stream->frame_rate); /* frames per seconds ? */
00252             avio_wb32(s,0);     /* unknown meaning */
00253             avio_wb16(s, (int) stream->frame_rate);  /* unknown meaning */
00254             avio_wb32(s,0);     /* unknown meaning */
00255             avio_wb16(s, 8);    /* unknown meaning */
00256             /* Seems to be the codec version: only use basic H263. The next
00257                versions seems to add a diffential DC coding as in
00258                MPEG... nothing new under the sun */
00259             if(stream->enc->codec_id == CODEC_ID_RV10)
00260                 avio_wb32(s,0x10000000);
00261             else
00262                 avio_wb32(s,0x20103001);
00263             //avio_wb32(s,0x10003000);
00264         }
00265     }
00266 
00267     /* patch data offset field */
00268     data_pos = s->buf_ptr - start_ptr;
00269     rm->data_pos = data_pos;
00270     data_offset_ptr[0] = data_pos >> 24;
00271     data_offset_ptr[1] = data_pos >> 16;
00272     data_offset_ptr[2] = data_pos >> 8;
00273     data_offset_ptr[3] = data_pos;
00274 
00275     /* data stream */
00276     ffio_wfourcc(s, "DATA");
00277     avio_wb32(s,data_size + 10 + 8);
00278     avio_wb16(s,0);
00279 
00280     avio_wb32(s, nb_packets); /* number of packets */
00281     avio_wb32(s,0); /* next data header */
00282     return 0;
00283 }
00284 
00285 static void write_packet_header(AVFormatContext *ctx, StreamInfo *stream,
00286                                 int length, int key_frame)
00287 {
00288     int timestamp;
00289     AVIOContext *s = ctx->pb;
00290 
00291     stream->nb_packets++;
00292     stream->packet_total_size += length;
00293     if (length > stream->packet_max_size)
00294         stream->packet_max_size =  length;
00295 
00296     avio_wb16(s,0); /* version */
00297     avio_wb16(s,length + 12);
00298     avio_wb16(s, stream->num); /* stream number */
00299     timestamp = (1000 * (float)stream->nb_frames) / stream->frame_rate;
00300     avio_wb32(s, timestamp); /* timestamp */
00301     avio_w8(s, 0); /* reserved */
00302     avio_w8(s, key_frame ? 2 : 0); /* flags */
00303 }
00304 
00305 static int rm_write_header(AVFormatContext *s)
00306 {
00307     RMMuxContext *rm = s->priv_data;
00308     StreamInfo *stream;
00309     int n;
00310     AVCodecContext *codec;
00311 
00312     for(n=0;n<s->nb_streams;n++) {
00313         s->streams[n]->id = n;
00314         codec = s->streams[n]->codec;
00315         stream = &rm->streams[n];
00316         memset(stream, 0, sizeof(StreamInfo));
00317         stream->num = n;
00318         stream->bit_rate = codec->bit_rate;
00319         stream->enc = codec;
00320 
00321         switch(codec->codec_type) {
00322         case AVMEDIA_TYPE_AUDIO:
00323             rm->audio_stream = stream;
00324             stream->frame_rate = (float)codec->sample_rate / (float)codec->frame_size;
00325             /* XXX: dummy values */
00326             stream->packet_max_size = 1024;
00327             stream->nb_packets = 0;
00328             stream->total_frames = stream->nb_packets;
00329             break;
00330         case AVMEDIA_TYPE_VIDEO:
00331             rm->video_stream = stream;
00332             stream->frame_rate = (float)codec->time_base.den / (float)codec->time_base.num;
00333             /* XXX: dummy values */
00334             stream->packet_max_size = 4096;
00335             stream->nb_packets = 0;
00336             stream->total_frames = stream->nb_packets;
00337             break;
00338         default:
00339             return -1;
00340         }
00341     }
00342 
00343     if (rv10_write_header(s, 0, 0))
00344         return AVERROR_INVALIDDATA;
00345     avio_flush(s->pb);
00346     return 0;
00347 }
00348 
00349 static int rm_write_audio(AVFormatContext *s, const uint8_t *buf, int size, int flags)
00350 {
00351     uint8_t *buf1;
00352     RMMuxContext *rm = s->priv_data;
00353     AVIOContext *pb = s->pb;
00354     StreamInfo *stream = rm->audio_stream;
00355     int i;
00356 
00357     /* XXX: suppress this malloc */
00358     buf1= (uint8_t*) av_malloc( size * sizeof(uint8_t) );
00359 
00360     write_packet_header(s, stream, size, !!(flags & AV_PKT_FLAG_KEY));
00361 
00362     if (stream->enc->codec_id == CODEC_ID_AC3) {
00363         /* for AC-3, the words seem to be reversed */
00364         for(i=0;i<size;i+=2) {
00365             buf1[i] = buf[i+1];
00366             buf1[i+1] = buf[i];
00367         }
00368         avio_write(pb, buf1, size);
00369     } else {
00370         avio_write(pb, buf, size);
00371     }
00372     avio_flush(pb);
00373     stream->nb_frames++;
00374     av_free(buf1);
00375     return 0;
00376 }
00377 
00378 static int rm_write_video(AVFormatContext *s, const uint8_t *buf, int size, int flags)
00379 {
00380     RMMuxContext *rm = s->priv_data;
00381     AVIOContext *pb = s->pb;
00382     StreamInfo *stream = rm->video_stream;
00383     int key_frame = !!(flags & AV_PKT_FLAG_KEY);
00384 
00385     /* XXX: this is incorrect: should be a parameter */
00386 
00387     /* Well, I spent some time finding the meaning of these bits. I am
00388        not sure I understood everything, but it works !! */
00389 #if 1
00390     write_packet_header(s, stream, size + 7 + (size >= 0x4000)*4, key_frame);
00391     /* bit 7: '1' if final packet of a frame converted in several packets */
00392     avio_w8(pb, 0x81);
00393     /* bit 7: '1' if I frame. bits 6..0 : sequence number in current
00394        frame starting from 1 */
00395     if (key_frame) {
00396         avio_w8(pb, 0x81);
00397     } else {
00398         avio_w8(pb, 0x01);
00399     }
00400     if(size >= 0x4000){
00401         avio_wb32(pb, size); /* total frame size */
00402         avio_wb32(pb, size); /* offset from the start or the end */
00403     }else{
00404         avio_wb16(pb, 0x4000 | size); /* total frame size */
00405         avio_wb16(pb, 0x4000 | size); /* offset from the start or the end */
00406     }
00407 #else
00408     /* full frame */
00409     write_packet_header(s, size + 6);
00410     avio_w8(pb, 0xc0);
00411     avio_wb16(pb, 0x4000 + size); /* total frame size */
00412     avio_wb16(pb, 0x4000 + packet_number * 126); /* position in stream */
00413 #endif
00414     avio_w8(pb, stream->nb_frames & 0xff);
00415 
00416     avio_write(pb, buf, size);
00417     avio_flush(pb);
00418 
00419     stream->nb_frames++;
00420     return 0;
00421 }
00422 
00423 static int rm_write_packet(AVFormatContext *s, AVPacket *pkt)
00424 {
00425     if (s->streams[pkt->stream_index]->codec->codec_type ==
00426         AVMEDIA_TYPE_AUDIO)
00427         return rm_write_audio(s, pkt->data, pkt->size, pkt->flags);
00428     else
00429         return rm_write_video(s, pkt->data, pkt->size, pkt->flags);
00430 }
00431 
00432 static int rm_write_trailer(AVFormatContext *s)
00433 {
00434     RMMuxContext *rm = s->priv_data;
00435     int data_size, index_pos, i;
00436     AVIOContext *pb = s->pb;
00437 
00438     if (s->pb->seekable) {
00439         /* end of file: finish to write header */
00440         index_pos = avio_tell(pb);
00441         data_size = index_pos - rm->data_pos;
00442 
00443         /* FIXME: write index */
00444 
00445         /* undocumented end header */
00446         avio_wb32(pb, 0);
00447         avio_wb32(pb, 0);
00448 
00449         avio_seek(pb, 0, SEEK_SET);
00450         for(i=0;i<s->nb_streams;i++)
00451             rm->streams[i].total_frames = rm->streams[i].nb_frames;
00452         rv10_write_header(s, data_size, 0);
00453     } else {
00454         /* undocumented end header */
00455         avio_wb32(pb, 0);
00456         avio_wb32(pb, 0);
00457     }
00458     avio_flush(pb);
00459     return 0;
00460 }
00461 
00462 
00463 AVOutputFormat ff_rm_muxer = {
00464     "rm",
00465     NULL_IF_CONFIG_SMALL("RealMedia format"),
00466     "application/vnd.rn-realmedia",
00467     "rm,ra",
00468     sizeof(RMMuxContext),
00469     CODEC_ID_AC3,
00470     CODEC_ID_RV10,
00471     rm_write_header,
00472     rm_write_packet,
00473     rm_write_trailer,
00474     .codec_tag= (const AVCodecTag* const []){ff_rm_codec_tags, 0},
00475 };