1/*
2 * "Real" compatible muxer.
3 * Copyright (c) 2000, 2001 Fabrice Bellard
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21#include "avformat.h"
22#include "avio_internal.h"
23#include "rm.h"
24#include "libavutil/dict.h"
25
26typedef struct {
27    int nb_packets;
28    int packet_total_size;
29    int packet_max_size;
30    /* codec related output */
31    int bit_rate;
32    float frame_rate;
33    int nb_frames;    /* current frame number */
34    int total_frames; /* total number of frames */
35    int num;
36    AVCodecContext *enc;
37} StreamInfo;
38
39typedef struct {
40    StreamInfo streams[2];
41    StreamInfo *audio_stream, *video_stream;
42    int data_pos; /* position of the data after the header */
43} RMMuxContext;
44
45/* in ms */
46#define BUFFER_DURATION 0
47
48
49static void put_str(AVIOContext *s, const char *tag)
50{
51    avio_wb16(s,strlen(tag));
52    while (*tag) {
53        avio_w8(s, *tag++);
54    }
55}
56
57static void put_str8(AVIOContext *s, const char *tag)
58{
59    avio_w8(s, strlen(tag));
60    while (*tag) {
61        avio_w8(s, *tag++);
62    }
63}
64
65static int rv10_write_header(AVFormatContext *ctx,
66                             int data_size, int index_pos)
67{
68    RMMuxContext *rm = ctx->priv_data;
69    AVIOContext *s = ctx->pb;
70    StreamInfo *stream;
71    unsigned char *data_offset_ptr, *start_ptr;
72    const char *desc, *mimetype;
73    int nb_packets, packet_total_size, packet_max_size, size, packet_avg_size, i;
74    int bit_rate, v, duration, flags, data_pos;
75    AVDictionaryEntry *tag;
76
77    start_ptr = s->buf_ptr;
78
79    ffio_wfourcc(s, ".RMF");
80    avio_wb32(s,18); /* header size */
81    avio_wb16(s,0);
82    avio_wb32(s,0);
83    avio_wb32(s,4 + ctx->nb_streams); /* num headers */
84
85    ffio_wfourcc(s,"PROP");
86    avio_wb32(s, 50);
87    avio_wb16(s, 0);
88    packet_max_size = 0;
89    packet_total_size = 0;
90    nb_packets = 0;
91    bit_rate = 0;
92    duration = 0;
93    for(i=0;i<ctx->nb_streams;i++) {
94        StreamInfo *stream = &rm->streams[i];
95        bit_rate += stream->bit_rate;
96        if (stream->packet_max_size > packet_max_size)
97            packet_max_size = stream->packet_max_size;
98        nb_packets += stream->nb_packets;
99        packet_total_size += stream->packet_total_size;
100        /* select maximum duration */
101        v = (int) (1000.0 * (float)stream->total_frames / stream->frame_rate);
102        if (v > duration)
103            duration = v;
104    }
105    avio_wb32(s, bit_rate); /* max bit rate */
106    avio_wb32(s, bit_rate); /* avg bit rate */
107    avio_wb32(s, packet_max_size);        /* max packet size */
108    if (nb_packets > 0)
109        packet_avg_size = packet_total_size / nb_packets;
110    else
111        packet_avg_size = 0;
112    avio_wb32(s, packet_avg_size);        /* avg packet size */
113    avio_wb32(s, nb_packets);  /* num packets */
114    avio_wb32(s, duration); /* duration */
115    avio_wb32(s, BUFFER_DURATION);           /* preroll */
116    avio_wb32(s, index_pos);           /* index offset */
117    /* computation of data the data offset */
118    data_offset_ptr = s->buf_ptr;
119    avio_wb32(s, 0);           /* data offset : will be patched after */
120    avio_wb16(s, ctx->nb_streams);    /* num streams */
121    flags = 1 | 2; /* save allowed & perfect play */
122    if (!s->seekable)
123        flags |= 4; /* live broadcast */
124    avio_wb16(s, flags);
125
126    /* comments */
127
128    ffio_wfourcc(s,"CONT");
129    size =  4 * 2 + 10;
130    for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) {
131        tag = av_dict_get(ctx->metadata, ff_rm_metadata[i], NULL, 0);
132        if(tag) size += strlen(tag->value);
133    }
134    avio_wb32(s,size);
135    avio_wb16(s,0);
136    for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) {
137        tag = av_dict_get(ctx->metadata, ff_rm_metadata[i], NULL, 0);
138        put_str(s, tag ? tag->value : "");
139    }
140
141    for(i=0;i<ctx->nb_streams;i++) {
142        int codec_data_size;
143
144        stream = &rm->streams[i];
145
146        if (stream->enc->codec_type == AVMEDIA_TYPE_AUDIO) {
147            desc = "The Audio Stream";
148            mimetype = "audio/x-pn-realaudio";
149            codec_data_size = 73;
150        } else {
151            desc = "The Video Stream";
152            mimetype = "video/x-pn-realvideo";
153            codec_data_size = 34;
154        }
155
156        ffio_wfourcc(s,"MDPR");
157        size = 10 + 9 * 4 + strlen(desc) + strlen(mimetype) + codec_data_size;
158        avio_wb32(s, size);
159        avio_wb16(s, 0);
160
161        avio_wb16(s, i); /* stream number */
162        avio_wb32(s, stream->bit_rate); /* max bit rate */
163        avio_wb32(s, stream->bit_rate); /* avg bit rate */
164        avio_wb32(s, stream->packet_max_size);        /* max packet size */
165        if (stream->nb_packets > 0)
166            packet_avg_size = stream->packet_total_size /
167                stream->nb_packets;
168        else
169            packet_avg_size = 0;
170        avio_wb32(s, packet_avg_size);        /* avg packet size */
171        avio_wb32(s, 0);           /* start time */
172        avio_wb32(s, BUFFER_DURATION);           /* preroll */
173        /* duration */
174        if (!s->seekable || !stream->total_frames)
175            avio_wb32(s, (int)(3600 * 1000));
176        else
177            avio_wb32(s, (int)(stream->total_frames * 1000 / stream->frame_rate));
178        put_str8(s, desc);
179        put_str8(s, mimetype);
180        avio_wb32(s, codec_data_size);
181
182        if (stream->enc->codec_type == AVMEDIA_TYPE_AUDIO) {
183            int coded_frame_size, fscode, sample_rate;
184            sample_rate = stream->enc->sample_rate;
185            coded_frame_size = (stream->enc->bit_rate *
186                                stream->enc->frame_size) / (8 * sample_rate);
187            /* audio codec info */
188            avio_write(s, ".ra", 3);
189            avio_w8(s, 0xfd);
190            avio_wb32(s, 0x00040000); /* version */
191            ffio_wfourcc(s, ".ra4");
192            avio_wb32(s, 0x01b53530); /* stream length */
193            avio_wb16(s, 4); /* unknown */
194            avio_wb32(s, 0x39); /* header size */
195
196            switch(sample_rate) {
197            case 48000:
198            case 24000:
199            case 12000:
200                fscode = 1;
201                break;
202            default:
203            case 44100:
204            case 22050:
205            case 11025:
206                fscode = 2;
207                break;
208            case 32000:
209            case 16000:
210            case 8000:
211                fscode = 3;
212            }
213            avio_wb16(s, fscode); /* codec additional info, for AC-3, seems
214                                     to be a frequency code */
215            /* special hack to compensate rounding errors... */
216            if (coded_frame_size == 557)
217                coded_frame_size--;
218            avio_wb32(s, coded_frame_size); /* frame length */
219            avio_wb32(s, 0x51540); /* unknown */
220            avio_wb32(s, stream->enc->bit_rate / 8 * 60); /* bytes per minute */
221            avio_wb32(s, stream->enc->bit_rate / 8 * 60); /* bytes per minute */
222            avio_wb16(s, 0x01);
223            /* frame length : seems to be very important */
224            avio_wb16(s, coded_frame_size);
225            avio_wb32(s, 0); /* unknown */
226            avio_wb16(s, stream->enc->sample_rate); /* sample rate */
227            avio_wb32(s, 0x10); /* unknown */
228            avio_wb16(s, stream->enc->channels);
229            put_str8(s, "Int0"); /* codec name */
230            if (stream->enc->codec_tag) {
231                avio_w8(s, 4); /* tag length */
232                avio_wl32(s, stream->enc->codec_tag);
233            } else {
234                av_log(ctx, AV_LOG_ERROR, "Invalid codec tag\n");
235                return -1;
236            }
237            avio_wb16(s, 0); /* title length */
238            avio_wb16(s, 0); /* author length */
239            avio_wb16(s, 0); /* copyright length */
240            avio_w8(s, 0); /* end of header */
241        } else {
242            /* video codec info */
243            avio_wb32(s,34); /* size */
244            ffio_wfourcc(s, "VIDO");
245            if(stream->enc->codec_id == AV_CODEC_ID_RV10)
246                ffio_wfourcc(s,"RV10");
247            else
248                ffio_wfourcc(s,"RV20");
249            avio_wb16(s, stream->enc->width);
250            avio_wb16(s, stream->enc->height);
251            avio_wb16(s, (int) stream->frame_rate); /* frames per seconds ? */
252            avio_wb32(s,0);     /* unknown meaning */
253            avio_wb16(s, (int) stream->frame_rate);  /* unknown meaning */
254            avio_wb32(s,0);     /* unknown meaning */
255            avio_wb16(s, 8);    /* unknown meaning */
256            /* Seems to be the codec version: only use basic H263. The next
257               versions seems to add a diffential DC coding as in
258               MPEG... nothing new under the sun */
259            if(stream->enc->codec_id == AV_CODEC_ID_RV10)
260                avio_wb32(s,0x10000000);
261            else
262                avio_wb32(s,0x20103001);
263            //avio_wb32(s,0x10003000);
264        }
265    }
266
267    /* patch data offset field */
268    data_pos = s->buf_ptr - start_ptr;
269    rm->data_pos = data_pos;
270    data_offset_ptr[0] = data_pos >> 24;
271    data_offset_ptr[1] = data_pos >> 16;
272    data_offset_ptr[2] = data_pos >> 8;
273    data_offset_ptr[3] = data_pos;
274
275    /* data stream */
276    ffio_wfourcc(s, "DATA");
277    avio_wb32(s,data_size + 10 + 8);
278    avio_wb16(s,0);
279
280    avio_wb32(s, nb_packets); /* number of packets */
281    avio_wb32(s,0); /* next data header */
282    return 0;
283}
284
285static void write_packet_header(AVFormatContext *ctx, StreamInfo *stream,
286                                int length, int key_frame)
287{
288    int timestamp;
289    AVIOContext *s = ctx->pb;
290
291    stream->nb_packets++;
292    stream->packet_total_size += length;
293    if (length > stream->packet_max_size)
294        stream->packet_max_size =  length;
295
296    avio_wb16(s,0); /* version */
297    avio_wb16(s,length + 12);
298    avio_wb16(s, stream->num); /* stream number */
299    timestamp = (1000 * (float)stream->nb_frames) / stream->frame_rate;
300    avio_wb32(s, timestamp); /* timestamp */
301    avio_w8(s, 0); /* reserved */
302    avio_w8(s, key_frame ? 2 : 0); /* flags */
303}
304
305static int rm_write_header(AVFormatContext *s)
306{
307    RMMuxContext *rm = s->priv_data;
308    StreamInfo *stream;
309    int n;
310    AVCodecContext *codec;
311
312    if (s->nb_streams > 2) {
313        av_log(s, AV_LOG_ERROR, "At most 2 streams are currently supported for muxing in RM\n");
314        return AVERROR_PATCHWELCOME;
315    }
316
317    for(n=0;n<s->nb_streams;n++) {
318        AVStream *st = s->streams[n];
319
320        s->streams[n]->id = n;
321        codec = s->streams[n]->codec;
322        stream = &rm->streams[n];
323        memset(stream, 0, sizeof(StreamInfo));
324        stream->num = n;
325        stream->bit_rate = codec->bit_rate;
326        stream->enc = codec;
327
328        switch(codec->codec_type) {
329        case AVMEDIA_TYPE_AUDIO:
330            rm->audio_stream = stream;
331            stream->frame_rate = (float)codec->sample_rate / (float)codec->frame_size;
332            /* XXX: dummy values */
333            stream->packet_max_size = 1024;
334            stream->nb_packets = 0;
335            stream->total_frames = stream->nb_packets;
336            break;
337        case AVMEDIA_TYPE_VIDEO:
338            rm->video_stream = stream;
339            // TODO: should be avg_frame_rate
340            stream->frame_rate = (float)st->time_base.den / (float)st->time_base.num;
341            /* XXX: dummy values */
342            stream->packet_max_size = 4096;
343            stream->nb_packets = 0;
344            stream->total_frames = stream->nb_packets;
345            break;
346        default:
347            return -1;
348        }
349    }
350
351    if (rv10_write_header(s, 0, 0))
352        return AVERROR_INVALIDDATA;
353    avio_flush(s->pb);
354    return 0;
355}
356
357static int rm_write_audio(AVFormatContext *s, const uint8_t *buf, int size, int flags)
358{
359    uint8_t *buf1;
360    RMMuxContext *rm = s->priv_data;
361    AVIOContext *pb = s->pb;
362    StreamInfo *stream = rm->audio_stream;
363    int i;
364
365    /* XXX: suppress this malloc */
366    buf1 = av_malloc(size * sizeof(uint8_t));
367
368    write_packet_header(s, stream, size, !!(flags & AV_PKT_FLAG_KEY));
369
370    if (stream->enc->codec_id == AV_CODEC_ID_AC3) {
371        /* for AC-3, the words seem to be reversed */
372        for(i=0;i<size;i+=2) {
373            buf1[i] = buf[i+1];
374            buf1[i+1] = buf[i];
375        }
376        avio_write(pb, buf1, size);
377    } else {
378        avio_write(pb, buf, size);
379    }
380    stream->nb_frames++;
381    av_free(buf1);
382    return 0;
383}
384
385static int rm_write_video(AVFormatContext *s, const uint8_t *buf, int size, int flags)
386{
387    RMMuxContext *rm = s->priv_data;
388    AVIOContext *pb = s->pb;
389    StreamInfo *stream = rm->video_stream;
390    int key_frame = !!(flags & AV_PKT_FLAG_KEY);
391
392    /* XXX: this is incorrect: should be a parameter */
393
394    /* Well, I spent some time finding the meaning of these bits. I am
395       not sure I understood everything, but it works !! */
396#if 1
397    write_packet_header(s, stream, size + 7 + (size >= 0x4000)*4, key_frame);
398    /* bit 7: '1' if final packet of a frame converted in several packets */
399    avio_w8(pb, 0x81);
400    /* bit 7: '1' if I frame. bits 6..0 : sequence number in current
401       frame starting from 1 */
402    if (key_frame) {
403        avio_w8(pb, 0x81);
404    } else {
405        avio_w8(pb, 0x01);
406    }
407    if(size >= 0x4000){
408        avio_wb32(pb, size); /* total frame size */
409        avio_wb32(pb, size); /* offset from the start or the end */
410    }else{
411        avio_wb16(pb, 0x4000 | size); /* total frame size */
412        avio_wb16(pb, 0x4000 | size); /* offset from the start or the end */
413    }
414#else
415    /* full frame */
416    write_packet_header(s, size + 6);
417    avio_w8(pb, 0xc0);
418    avio_wb16(pb, 0x4000 + size); /* total frame size */
419    avio_wb16(pb, 0x4000 + packet_number * 126); /* position in stream */
420#endif
421    avio_w8(pb, stream->nb_frames & 0xff);
422
423    avio_write(pb, buf, size);
424
425    stream->nb_frames++;
426    return 0;
427}
428
429static int rm_write_packet(AVFormatContext *s, AVPacket *pkt)
430{
431    if (s->streams[pkt->stream_index]->codec->codec_type ==
432        AVMEDIA_TYPE_AUDIO)
433        return rm_write_audio(s, pkt->data, pkt->size, pkt->flags);
434    else
435        return rm_write_video(s, pkt->data, pkt->size, pkt->flags);
436}
437
438static int rm_write_trailer(AVFormatContext *s)
439{
440    RMMuxContext *rm = s->priv_data;
441    int data_size, index_pos, i;
442    AVIOContext *pb = s->pb;
443
444    if (s->pb->seekable) {
445        /* end of file: finish to write header */
446        index_pos = avio_tell(pb);
447        data_size = index_pos - rm->data_pos;
448
449        /* FIXME: write index */
450
451        /* undocumented end header */
452        avio_wb32(pb, 0);
453        avio_wb32(pb, 0);
454
455        avio_seek(pb, 0, SEEK_SET);
456        for(i=0;i<s->nb_streams;i++)
457            rm->streams[i].total_frames = rm->streams[i].nb_frames;
458        rv10_write_header(s, data_size, 0);
459    } else {
460        /* undocumented end header */
461        avio_wb32(pb, 0);
462        avio_wb32(pb, 0);
463    }
464
465    return 0;
466}
467
468
469AVOutputFormat ff_rm_muxer = {
470    .name              = "rm",
471    .long_name         = NULL_IF_CONFIG_SMALL("RealMedia"),
472    .mime_type         = "application/vnd.rn-realmedia",
473    .extensions        = "rm,ra",
474    .priv_data_size    = sizeof(RMMuxContext),
475    .audio_codec       = AV_CODEC_ID_AC3,
476    .video_codec       = AV_CODEC_ID_RV10,
477    .write_header      = rm_write_header,
478    .write_packet      = rm_write_packet,
479    .write_trailer     = rm_write_trailer,
480    .codec_tag         = (const AVCodecTag* const []){ ff_rm_codec_tags, 0 },
481};
482