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 "rm.h"
00023 
00024 typedef struct {
00025     int nb_packets;
00026     int packet_total_size;
00027     int packet_max_size;
00028     /* codec related output */
00029     int bit_rate;
00030     float frame_rate;
00031     int nb_frames;    /* current frame number */
00032     int total_frames; /* total number of frames */
00033     int num;
00034     AVCodecContext *enc;
00035 } StreamInfo;
00036 
00037 typedef struct {
00038     StreamInfo streams[2];
00039     StreamInfo *audio_stream, *video_stream;
00040     int data_pos; /* position of the data after the header */
00041 } RMMuxContext;
00042 
00043 /* in ms */
00044 #define BUFFER_DURATION 0
00045 
00046 
00047 static void put_str(ByteIOContext *s, const char *tag)
00048 {
00049     put_be16(s,strlen(tag));
00050     while (*tag) {
00051         put_byte(s, *tag++);
00052     }
00053 }
00054 
00055 static void put_str8(ByteIOContext *s, const char *tag)
00056 {
00057     put_byte(s, strlen(tag));
00058     while (*tag) {
00059         put_byte(s, *tag++);
00060     }
00061 }
00062 
00063 static int rv10_write_header(AVFormatContext *ctx,
00064                              int data_size, int index_pos)
00065 {
00066     RMMuxContext *rm = ctx->priv_data;
00067     ByteIOContext *s = ctx->pb;
00068     StreamInfo *stream;
00069     unsigned char *data_offset_ptr, *start_ptr;
00070     const char *desc, *mimetype;
00071     int nb_packets, packet_total_size, packet_max_size, size, packet_avg_size, i;
00072     int bit_rate, v, duration, flags, data_pos;
00073     AVMetadataTag *tag;
00074 
00075     start_ptr = s->buf_ptr;
00076 
00077     put_tag(s, ".RMF");
00078     put_be32(s,18); /* header size */
00079     put_be16(s,0);
00080     put_be32(s,0);
00081     put_be32(s,4 + ctx->nb_streams); /* num headers */
00082 
00083     put_tag(s,"PROP");
00084     put_be32(s, 50);
00085     put_be16(s, 0);
00086     packet_max_size = 0;
00087     packet_total_size = 0;
00088     nb_packets = 0;
00089     bit_rate = 0;
00090     duration = 0;
00091     for(i=0;i<ctx->nb_streams;i++) {
00092         StreamInfo *stream = &rm->streams[i];
00093         bit_rate += stream->bit_rate;
00094         if (stream->packet_max_size > packet_max_size)
00095             packet_max_size = stream->packet_max_size;
00096         nb_packets += stream->nb_packets;
00097         packet_total_size += stream->packet_total_size;
00098         /* select maximum duration */
00099         v = (int) (1000.0 * (float)stream->total_frames / stream->frame_rate);
00100         if (v > duration)
00101             duration = v;
00102     }
00103     put_be32(s, bit_rate); /* max bit rate */
00104     put_be32(s, bit_rate); /* avg bit rate */
00105     put_be32(s, packet_max_size);        /* max packet size */
00106     if (nb_packets > 0)
00107         packet_avg_size = packet_total_size / nb_packets;
00108     else
00109         packet_avg_size = 0;
00110     put_be32(s, packet_avg_size);        /* avg packet size */
00111     put_be32(s, nb_packets);  /* num packets */
00112     put_be32(s, duration); /* duration */
00113     put_be32(s, BUFFER_DURATION);           /* preroll */
00114     put_be32(s, index_pos);           /* index offset */
00115     /* computation of data the data offset */
00116     data_offset_ptr = s->buf_ptr;
00117     put_be32(s, 0);           /* data offset : will be patched after */
00118     put_be16(s, ctx->nb_streams);    /* num streams */
00119     flags = 1 | 2; /* save allowed & perfect play */
00120     if (url_is_streamed(s))
00121         flags |= 4; /* live broadcast */
00122     put_be16(s, flags);
00123 
00124     /* comments */
00125 
00126     put_tag(s,"CONT");
00127     size =  4 * 2 + 10;
00128     for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) {
00129         tag = av_metadata_get(ctx->metadata, ff_rm_metadata[i], NULL, 0);
00130         if(tag) size += strlen(tag->value);
00131     }
00132     put_be32(s,size);
00133     put_be16(s,0);
00134     for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) {
00135         tag = av_metadata_get(ctx->metadata, ff_rm_metadata[i], NULL, 0);
00136         put_str(s, tag ? tag->value : "");
00137     }
00138 
00139     for(i=0;i<ctx->nb_streams;i++) {
00140         int codec_data_size;
00141 
00142         stream = &rm->streams[i];
00143 
00144         if (stream->enc->codec_type == AVMEDIA_TYPE_AUDIO) {
00145             desc = "The Audio Stream";
00146             mimetype = "audio/x-pn-realaudio";
00147             codec_data_size = 73;
00148         } else {
00149             desc = "The Video Stream";
00150             mimetype = "video/x-pn-realvideo";
00151             codec_data_size = 34;
00152         }
00153 
00154         put_tag(s,"MDPR");
00155         size = 10 + 9 * 4 + strlen(desc) + strlen(mimetype) + codec_data_size;
00156         put_be32(s, size);
00157         put_be16(s, 0);
00158 
00159         put_be16(s, i); /* stream number */
00160         put_be32(s, stream->bit_rate); /* max bit rate */
00161         put_be32(s, stream->bit_rate); /* avg bit rate */
00162         put_be32(s, stream->packet_max_size);        /* max packet size */
00163         if (stream->nb_packets > 0)
00164             packet_avg_size = stream->packet_total_size /
00165                 stream->nb_packets;
00166         else
00167             packet_avg_size = 0;
00168         put_be32(s, packet_avg_size);        /* avg packet size */
00169         put_be32(s, 0);           /* start time */
00170         put_be32(s, BUFFER_DURATION);           /* preroll */
00171         /* duration */
00172         if (url_is_streamed(s) || !stream->total_frames)
00173             put_be32(s, (int)(3600 * 1000));
00174         else
00175             put_be32(s, (int)(stream->total_frames * 1000 / stream->frame_rate));
00176         put_str8(s, desc);
00177         put_str8(s, mimetype);
00178         put_be32(s, codec_data_size);
00179 
00180         if (stream->enc->codec_type == AVMEDIA_TYPE_AUDIO) {
00181             int coded_frame_size, fscode, sample_rate;
00182             sample_rate = stream->enc->sample_rate;
00183             coded_frame_size = (stream->enc->bit_rate *
00184                                 stream->enc->frame_size) / (8 * sample_rate);
00185             /* audio codec info */
00186             put_tag(s, ".ra");
00187             put_byte(s, 0xfd);
00188             put_be32(s, 0x00040000); /* version */
00189             put_tag(s, ".ra4");
00190             put_be32(s, 0x01b53530); /* stream length */
00191             put_be16(s, 4); /* unknown */
00192             put_be32(s, 0x39); /* header size */
00193 
00194             switch(sample_rate) {
00195             case 48000:
00196             case 24000:
00197             case 12000:
00198                 fscode = 1;
00199                 break;
00200             default:
00201             case 44100:
00202             case 22050:
00203             case 11025:
00204                 fscode = 2;
00205                 break;
00206             case 32000:
00207             case 16000:
00208             case 8000:
00209                 fscode = 3;
00210             }
00211             put_be16(s, fscode); /* codec additional info, for AC-3, seems
00212                                      to be a frequency code */
00213             /* special hack to compensate rounding errors... */
00214             if (coded_frame_size == 557)
00215                 coded_frame_size--;
00216             put_be32(s, coded_frame_size); /* frame length */
00217             put_be32(s, 0x51540); /* unknown */
00218             put_be32(s, 0x249f0); /* unknown */
00219             put_be32(s, 0x249f0); /* unknown */
00220             put_be16(s, 0x01);
00221             /* frame length : seems to be very important */
00222             put_be16(s, coded_frame_size);
00223             put_be32(s, 0); /* unknown */
00224             put_be16(s, stream->enc->sample_rate); /* sample rate */
00225             put_be32(s, 0x10); /* unknown */
00226             put_be16(s, stream->enc->channels);
00227             put_str8(s, "Int0"); /* codec name */
00228             if (stream->enc->codec_tag) {
00229                 put_byte(s, 4); /* tag length */
00230                 put_le32(s, stream->enc->codec_tag);
00231             } else {
00232                 av_log(ctx, AV_LOG_ERROR, "Invalid codec tag\n");
00233                 return -1;
00234             }
00235             put_be16(s, 0); /* title length */
00236             put_be16(s, 0); /* author length */
00237             put_be16(s, 0); /* copyright length */
00238             put_byte(s, 0); /* end of header */
00239         } else {
00240             /* video codec info */
00241             put_be32(s,34); /* size */
00242             if(stream->enc->codec_id == CODEC_ID_RV10)
00243                 put_tag(s,"VIDORV10");
00244             else
00245                 put_tag(s,"VIDORV20");
00246             put_be16(s, stream->enc->width);
00247             put_be16(s, stream->enc->height);
00248             put_be16(s, (int) stream->frame_rate); /* frames per seconds ? */
00249             put_be32(s,0);     /* unknown meaning */
00250             put_be16(s, (int) stream->frame_rate);  /* unknown meaning */
00251             put_be32(s,0);     /* unknown meaning */
00252             put_be16(s, 8);    /* unknown meaning */
00253             /* Seems to be the codec version: only use basic H263. The next
00254                versions seems to add a diffential DC coding as in
00255                MPEG... nothing new under the sun */
00256             if(stream->enc->codec_id == CODEC_ID_RV10)
00257                 put_be32(s,0x10000000);
00258             else
00259                 put_be32(s,0x20103001);
00260             //put_be32(s,0x10003000);
00261         }
00262     }
00263 
00264     /* patch data offset field */
00265     data_pos = s->buf_ptr - start_ptr;
00266     rm->data_pos = data_pos;
00267     data_offset_ptr[0] = data_pos >> 24;
00268     data_offset_ptr[1] = data_pos >> 16;
00269     data_offset_ptr[2] = data_pos >> 8;
00270     data_offset_ptr[3] = data_pos;
00271 
00272     /* data stream */
00273     put_tag(s,"DATA");
00274     put_be32(s,data_size + 10 + 8);
00275     put_be16(s,0);
00276 
00277     put_be32(s, nb_packets); /* number of packets */
00278     put_be32(s,0); /* next data header */
00279     return 0;
00280 }
00281 
00282 static void write_packet_header(AVFormatContext *ctx, StreamInfo *stream,
00283                                 int length, int key_frame)
00284 {
00285     int timestamp;
00286     ByteIOContext *s = ctx->pb;
00287 
00288     stream->nb_packets++;
00289     stream->packet_total_size += length;
00290     if (length > stream->packet_max_size)
00291         stream->packet_max_size =  length;
00292 
00293     put_be16(s,0); /* version */
00294     put_be16(s,length + 12);
00295     put_be16(s, stream->num); /* stream number */
00296     timestamp = (1000 * (float)stream->nb_frames) / stream->frame_rate;
00297     put_be32(s, timestamp); /* timestamp */
00298     put_byte(s, 0); /* reserved */
00299     put_byte(s, key_frame ? 2 : 0); /* flags */
00300 }
00301 
00302 static int rm_write_header(AVFormatContext *s)
00303 {
00304     RMMuxContext *rm = s->priv_data;
00305     StreamInfo *stream;
00306     int n;
00307     AVCodecContext *codec;
00308 
00309     for(n=0;n<s->nb_streams;n++) {
00310         s->streams[n]->id = n;
00311         codec = s->streams[n]->codec;
00312         stream = &rm->streams[n];
00313         memset(stream, 0, sizeof(StreamInfo));
00314         stream->num = n;
00315         stream->bit_rate = codec->bit_rate;
00316         stream->enc = codec;
00317 
00318         switch(codec->codec_type) {
00319         case AVMEDIA_TYPE_AUDIO:
00320             rm->audio_stream = stream;
00321             stream->frame_rate = (float)codec->sample_rate / (float)codec->frame_size;
00322             /* XXX: dummy values */
00323             stream->packet_max_size = 1024;
00324             stream->nb_packets = 0;
00325             stream->total_frames = stream->nb_packets;
00326             break;
00327         case AVMEDIA_TYPE_VIDEO:
00328             rm->video_stream = stream;
00329             stream->frame_rate = (float)codec->time_base.den / (float)codec->time_base.num;
00330             /* XXX: dummy values */
00331             stream->packet_max_size = 4096;
00332             stream->nb_packets = 0;
00333             stream->total_frames = stream->nb_packets;
00334             break;
00335         default:
00336             return -1;
00337         }
00338     }
00339 
00340     if (rv10_write_header(s, 0, 0))
00341         return AVERROR_INVALIDDATA;
00342     put_flush_packet(s->pb);
00343     return 0;
00344 }
00345 
00346 static int rm_write_audio(AVFormatContext *s, const uint8_t *buf, int size, int flags)
00347 {
00348     uint8_t *buf1;
00349     RMMuxContext *rm = s->priv_data;
00350     ByteIOContext *pb = s->pb;
00351     StreamInfo *stream = rm->audio_stream;
00352     int i;
00353 
00354     /* XXX: suppress this malloc */
00355     buf1= (uint8_t*) av_malloc( size * sizeof(uint8_t) );
00356 
00357     write_packet_header(s, stream, size, !!(flags & AV_PKT_FLAG_KEY));
00358 
00359     if (stream->enc->codec_id == CODEC_ID_AC3) {
00360         /* for AC-3, the words seem to be reversed */
00361         for(i=0;i<size;i+=2) {
00362             buf1[i] = buf[i+1];
00363             buf1[i+1] = buf[i];
00364         }
00365         put_buffer(pb, buf1, size);
00366     } else {
00367         put_buffer(pb, buf, size);
00368     }
00369     put_flush_packet(pb);
00370     stream->nb_frames++;
00371     av_free(buf1);
00372     return 0;
00373 }
00374 
00375 static int rm_write_video(AVFormatContext *s, const uint8_t *buf, int size, int flags)
00376 {
00377     RMMuxContext *rm = s->priv_data;
00378     ByteIOContext *pb = s->pb;
00379     StreamInfo *stream = rm->video_stream;
00380     int key_frame = !!(flags & AV_PKT_FLAG_KEY);
00381 
00382     /* XXX: this is incorrect: should be a parameter */
00383 
00384     /* Well, I spent some time finding the meaning of these bits. I am
00385        not sure I understood everything, but it works !! */
00386 #if 1
00387     write_packet_header(s, stream, size + 7 + (size >= 0x4000)*4, key_frame);
00388     /* bit 7: '1' if final packet of a frame converted in several packets */
00389     put_byte(pb, 0x81);
00390     /* bit 7: '1' if I frame. bits 6..0 : sequence number in current
00391        frame starting from 1 */
00392     if (key_frame) {
00393         put_byte(pb, 0x81);
00394     } else {
00395         put_byte(pb, 0x01);
00396     }
00397     if(size >= 0x4000){
00398         put_be32(pb, size); /* total frame size */
00399         put_be32(pb, size); /* offset from the start or the end */
00400     }else{
00401         put_be16(pb, 0x4000 | size); /* total frame size */
00402         put_be16(pb, 0x4000 | size); /* offset from the start or the end */
00403     }
00404 #else
00405     /* full frame */
00406     write_packet_header(s, size + 6);
00407     put_byte(pb, 0xc0);
00408     put_be16(pb, 0x4000 + size); /* total frame size */
00409     put_be16(pb, 0x4000 + packet_number * 126); /* position in stream */
00410 #endif
00411     put_byte(pb, stream->nb_frames & 0xff);
00412 
00413     put_buffer(pb, buf, size);
00414     put_flush_packet(pb);
00415 
00416     stream->nb_frames++;
00417     return 0;
00418 }
00419 
00420 static int rm_write_packet(AVFormatContext *s, AVPacket *pkt)
00421 {
00422     if (s->streams[pkt->stream_index]->codec->codec_type ==
00423         AVMEDIA_TYPE_AUDIO)
00424         return rm_write_audio(s, pkt->data, pkt->size, pkt->flags);
00425     else
00426         return rm_write_video(s, pkt->data, pkt->size, pkt->flags);
00427 }
00428 
00429 static int rm_write_trailer(AVFormatContext *s)
00430 {
00431     RMMuxContext *rm = s->priv_data;
00432     int data_size, index_pos, i;
00433     ByteIOContext *pb = s->pb;
00434 
00435     if (!url_is_streamed(s->pb)) {
00436         /* end of file: finish to write header */
00437         index_pos = url_fseek(pb, 0, SEEK_CUR);
00438         data_size = index_pos - rm->data_pos;
00439 
00440         /* FIXME: write index */
00441 
00442         /* undocumented end header */
00443         put_be32(pb, 0);
00444         put_be32(pb, 0);
00445 
00446         url_fseek(pb, 0, SEEK_SET);
00447         for(i=0;i<s->nb_streams;i++)
00448             rm->streams[i].total_frames = rm->streams[i].nb_frames;
00449         rv10_write_header(s, data_size, 0);
00450     } else {
00451         /* undocumented end header */
00452         put_be32(pb, 0);
00453         put_be32(pb, 0);
00454     }
00455     put_flush_packet(pb);
00456     return 0;
00457 }
00458 
00459 
00460 AVOutputFormat rm_muxer = {
00461     "rm",
00462     NULL_IF_CONFIG_SMALL("RealMedia format"),
00463     "application/vnd.rn-realmedia",
00464     "rm,ra",
00465     sizeof(RMMuxContext),
00466     CODEC_ID_AC3,
00467     CODEC_ID_RV10,
00468     rm_write_header,
00469     rm_write_packet,
00470     rm_write_trailer,
00471     .codec_tag= (const AVCodecTag* const []){ff_rm_codec_tags, 0},
00472 };