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 == AV_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 == AV_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     if (s->nb_streams > 2) {
00313         av_log(s, AV_LOG_ERROR, "At most 2 streams are currently supported for muxing in RM\n");
00314         return AVERROR_PATCHWELCOME;
00315     }
00316 
00317     for(n=0;n<s->nb_streams;n++) {
00318         s->streams[n]->id = n;
00319         codec = s->streams[n]->codec;
00320         stream = &rm->streams[n];
00321         memset(stream, 0, sizeof(StreamInfo));
00322         stream->num = n;
00323         stream->bit_rate = codec->bit_rate;
00324         stream->enc = codec;
00325 
00326         switch(codec->codec_type) {
00327         case AVMEDIA_TYPE_AUDIO:
00328             rm->audio_stream = stream;
00329             stream->frame_rate = (float)codec->sample_rate / (float)codec->frame_size;
00330             /* XXX: dummy values */
00331             stream->packet_max_size = 1024;
00332             stream->nb_packets = 0;
00333             stream->total_frames = stream->nb_packets;
00334             break;
00335         case AVMEDIA_TYPE_VIDEO:
00336             rm->video_stream = stream;
00337             stream->frame_rate = (float)codec->time_base.den / (float)codec->time_base.num;
00338             /* XXX: dummy values */
00339             stream->packet_max_size = 4096;
00340             stream->nb_packets = 0;
00341             stream->total_frames = stream->nb_packets;
00342             break;
00343         default:
00344             return -1;
00345         }
00346     }
00347 
00348     if (rv10_write_header(s, 0, 0))
00349         return AVERROR_INVALIDDATA;
00350     avio_flush(s->pb);
00351     return 0;
00352 }
00353 
00354 static int rm_write_audio(AVFormatContext *s, const uint8_t *buf, int size, int flags)
00355 {
00356     uint8_t *buf1;
00357     RMMuxContext *rm = s->priv_data;
00358     AVIOContext *pb = s->pb;
00359     StreamInfo *stream = rm->audio_stream;
00360     int i;
00361 
00362     /* XXX: suppress this malloc */
00363     buf1 = av_malloc(size * sizeof(uint8_t));
00364 
00365     write_packet_header(s, stream, size, !!(flags & AV_PKT_FLAG_KEY));
00366 
00367     if (stream->enc->codec_id == AV_CODEC_ID_AC3) {
00368         /* for AC-3, the words seem to be reversed */
00369         for(i=0;i<size;i+=2) {
00370             buf1[i] = buf[i+1];
00371             buf1[i+1] = buf[i];
00372         }
00373         avio_write(pb, buf1, size);
00374     } else {
00375         avio_write(pb, buf, size);
00376     }
00377     avio_flush(pb);
00378     stream->nb_frames++;
00379     av_free(buf1);
00380     return 0;
00381 }
00382 
00383 static int rm_write_video(AVFormatContext *s, const uint8_t *buf, int size, int flags)
00384 {
00385     RMMuxContext *rm = s->priv_data;
00386     AVIOContext *pb = s->pb;
00387     StreamInfo *stream = rm->video_stream;
00388     int key_frame = !!(flags & AV_PKT_FLAG_KEY);
00389 
00390     /* XXX: this is incorrect: should be a parameter */
00391 
00392     /* Well, I spent some time finding the meaning of these bits. I am
00393        not sure I understood everything, but it works !! */
00394 #if 1
00395     write_packet_header(s, stream, size + 7 + (size >= 0x4000)*4, key_frame);
00396     /* bit 7: '1' if final packet of a frame converted in several packets */
00397     avio_w8(pb, 0x81);
00398     /* bit 7: '1' if I frame. bits 6..0 : sequence number in current
00399        frame starting from 1 */
00400     if (key_frame) {
00401         avio_w8(pb, 0x81);
00402     } else {
00403         avio_w8(pb, 0x01);
00404     }
00405     if(size >= 0x4000){
00406         avio_wb32(pb, size); /* total frame size */
00407         avio_wb32(pb, size); /* offset from the start or the end */
00408     }else{
00409         avio_wb16(pb, 0x4000 | size); /* total frame size */
00410         avio_wb16(pb, 0x4000 | size); /* offset from the start or the end */
00411     }
00412 #else
00413     /* full frame */
00414     write_packet_header(s, size + 6);
00415     avio_w8(pb, 0xc0);
00416     avio_wb16(pb, 0x4000 + size); /* total frame size */
00417     avio_wb16(pb, 0x4000 + packet_number * 126); /* position in stream */
00418 #endif
00419     avio_w8(pb, stream->nb_frames & 0xff);
00420 
00421     avio_write(pb, buf, size);
00422     avio_flush(pb);
00423 
00424     stream->nb_frames++;
00425     return 0;
00426 }
00427 
00428 static int rm_write_packet(AVFormatContext *s, AVPacket *pkt)
00429 {
00430     if (s->streams[pkt->stream_index]->codec->codec_type ==
00431         AVMEDIA_TYPE_AUDIO)
00432         return rm_write_audio(s, pkt->data, pkt->size, pkt->flags);
00433     else
00434         return rm_write_video(s, pkt->data, pkt->size, pkt->flags);
00435 }
00436 
00437 static int rm_write_trailer(AVFormatContext *s)
00438 {
00439     RMMuxContext *rm = s->priv_data;
00440     int data_size, index_pos, i;
00441     AVIOContext *pb = s->pb;
00442 
00443     if (s->pb->seekable) {
00444         /* end of file: finish to write header */
00445         index_pos = avio_tell(pb);
00446         data_size = index_pos - rm->data_pos;
00447 
00448         /* FIXME: write index */
00449 
00450         /* undocumented end header */
00451         avio_wb32(pb, 0);
00452         avio_wb32(pb, 0);
00453 
00454         avio_seek(pb, 0, SEEK_SET);
00455         for(i=0;i<s->nb_streams;i++)
00456             rm->streams[i].total_frames = rm->streams[i].nb_frames;
00457         rv10_write_header(s, data_size, 0);
00458     } else {
00459         /* undocumented end header */
00460         avio_wb32(pb, 0);
00461         avio_wb32(pb, 0);
00462     }
00463 
00464     return 0;
00465 }
00466 
00467 
00468 AVOutputFormat ff_rm_muxer = {
00469     .name              = "rm",
00470     .long_name         = NULL_IF_CONFIG_SMALL("RealMedia"),
00471     .mime_type         = "application/vnd.rn-realmedia",
00472     .extensions        = "rm,ra",
00473     .priv_data_size    = sizeof(RMMuxContext),
00474     .audio_codec       = AV_CODEC_ID_AC3,
00475     .video_codec       = AV_CODEC_ID_RV10,
00476     .write_header      = rm_write_header,
00477     .write_packet      = rm_write_packet,
00478     .write_trailer     = rm_write_trailer,
00479     .codec_tag         = (const AVCodecTag* const []){ ff_rm_codec_tags, 0 },
00480 };