xref: /third_party/ffmpeg/libavformat/rmenc.c (revision cabdff1a)
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 StreamInfo {
27    int nb_packets;
28    int packet_total_size;
29    int packet_max_size;
30    /* codec related output */
31    int bit_rate;
32    AVRational frame_rate;
33    int nb_frames;    /* current frame number */
34    int total_frames; /* total number of frames */
35    int num;
36    AVCodecParameters *par;
37} StreamInfo;
38
39typedef struct RMMuxContext {
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/* the header needs at most 7 + 4 + 12 B */
48#define MAX_HEADER_SIZE (7 + 4 + 12)
49/* UINT16_MAX is the maximal chunk size */
50#define MAX_PACKET_SIZE (UINT16_MAX - MAX_HEADER_SIZE)
51
52
53static void put_str(AVIOContext *s, const char *tag)
54{
55    avio_wb16(s,strlen(tag));
56    while (*tag) {
57        avio_w8(s, *tag++);
58    }
59}
60
61static void put_str8(AVIOContext *s, const char *tag)
62{
63    avio_w8(s, strlen(tag));
64    while (*tag) {
65        avio_w8(s, *tag++);
66    }
67}
68
69static int rv10_write_header(AVFormatContext *ctx,
70                             int data_size, int index_pos)
71{
72    RMMuxContext *rm = ctx->priv_data;
73    AVIOContext *s = ctx->pb;
74    StreamInfo *stream;
75    const char *desc, *mimetype;
76    int nb_packets, packet_total_size, packet_max_size, size, packet_avg_size, i;
77    int bit_rate, v, duration, flags;
78    int data_offset;
79    AVDictionaryEntry *tag;
80
81    ffio_wfourcc(s, ".RMF");
82    avio_wb32(s,18); /* header size */
83    avio_wb16(s,0);
84    avio_wb32(s,0);
85    avio_wb32(s,4 + ctx->nb_streams); /* num headers */
86
87    ffio_wfourcc(s,"PROP");
88    avio_wb32(s, 50);
89    avio_wb16(s, 0);
90    packet_max_size = 0;
91    packet_total_size = 0;
92    nb_packets = 0;
93    bit_rate = 0;
94    duration = 0;
95    for(i=0;i<ctx->nb_streams;i++) {
96        StreamInfo *stream = &rm->streams[i];
97        bit_rate += stream->bit_rate;
98        if (stream->packet_max_size > packet_max_size)
99            packet_max_size = stream->packet_max_size;
100        nb_packets += stream->nb_packets;
101        packet_total_size += stream->packet_total_size;
102        /* select maximum duration */
103        v = av_rescale_q_rnd(stream->total_frames, (AVRational){1000, 1}, stream->frame_rate, AV_ROUND_ZERO);
104        if (v > duration)
105            duration = v;
106    }
107    avio_wb32(s, bit_rate); /* max bit rate */
108    avio_wb32(s, bit_rate); /* avg bit rate */
109    avio_wb32(s, packet_max_size);        /* max packet size */
110    if (nb_packets > 0)
111        packet_avg_size = packet_total_size / nb_packets;
112    else
113        packet_avg_size = 0;
114    avio_wb32(s, packet_avg_size);        /* avg packet size */
115    avio_wb32(s, nb_packets);  /* num packets */
116    avio_wb32(s, duration); /* duration */
117    avio_wb32(s, BUFFER_DURATION);           /* preroll */
118    avio_wb32(s, index_pos);           /* index offset */
119    /* computation of data the data offset */
120    data_offset = avio_tell(s);
121    avio_wb32(s, 0);           /* data offset : will be patched after */
122    avio_wb16(s, ctx->nb_streams);    /* num streams */
123    flags = 1 | 2; /* save allowed & perfect play */
124    if (!(s->seekable & AVIO_SEEKABLE_NORMAL))
125        flags |= 4; /* live broadcast */
126    avio_wb16(s, flags);
127
128    /* comments */
129
130    ffio_wfourcc(s,"CONT");
131    size =  4 * 2 + 10;
132    for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) {
133        tag = av_dict_get(ctx->metadata, ff_rm_metadata[i], NULL, 0);
134        if(tag) size += strlen(tag->value);
135    }
136    avio_wb32(s,size);
137    avio_wb16(s,0);
138    for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) {
139        tag = av_dict_get(ctx->metadata, ff_rm_metadata[i], NULL, 0);
140        put_str(s, tag ? tag->value : "");
141    }
142
143    for(i=0;i<ctx->nb_streams;i++) {
144        int codec_data_size;
145
146        stream = &rm->streams[i];
147
148        if (stream->par->codec_type == AVMEDIA_TYPE_AUDIO) {
149            desc = "The Audio Stream";
150            mimetype = "audio/x-pn-realaudio";
151            codec_data_size = 73;
152        } else {
153            desc = "The Video Stream";
154            mimetype = "video/x-pn-realvideo";
155            codec_data_size = 34;
156        }
157
158        ffio_wfourcc(s,"MDPR");
159        size = 10 + 9 * 4 + strlen(desc) + strlen(mimetype) + codec_data_size;
160        avio_wb32(s, size);
161        avio_wb16(s, 0);
162
163        avio_wb16(s, i); /* stream number */
164        avio_wb32(s, stream->bit_rate); /* max bit rate */
165        avio_wb32(s, stream->bit_rate); /* avg bit rate */
166        avio_wb32(s, stream->packet_max_size);        /* max packet size */
167        if (stream->nb_packets > 0)
168            packet_avg_size = stream->packet_total_size /
169                stream->nb_packets;
170        else
171            packet_avg_size = 0;
172        avio_wb32(s, packet_avg_size);        /* avg packet size */
173        avio_wb32(s, 0);           /* start time */
174        avio_wb32(s, BUFFER_DURATION);           /* preroll */
175        /* duration */
176        if (!(s->seekable & AVIO_SEEKABLE_NORMAL) || !stream->total_frames)
177            avio_wb32(s, (int)(3600 * 1000));
178        else
179            avio_wb32(s, av_rescale_q_rnd(stream->total_frames, (AVRational){1000, 1},  stream->frame_rate, AV_ROUND_ZERO));
180        put_str8(s, desc);
181        put_str8(s, mimetype);
182        avio_wb32(s, codec_data_size);
183
184        if (stream->par->codec_type == AVMEDIA_TYPE_AUDIO) {
185            int coded_frame_size, fscode, sample_rate;
186            int frame_size = av_get_audio_frame_duration2(stream->par, 0);
187            sample_rate = stream->par->sample_rate;
188            coded_frame_size = (stream->par->bit_rate *
189                                frame_size) / (8 * sample_rate);
190            /* audio codec info */
191            avio_write(s, ".ra", 3);
192            avio_w8(s, 0xfd);
193            avio_wb32(s, 0x00040000); /* version */
194            ffio_wfourcc(s, ".ra4");
195            avio_wb32(s, 0x01b53530); /* stream length */
196            avio_wb16(s, 4); /* unknown */
197            avio_wb32(s, 0x39); /* header size */
198
199            switch(sample_rate) {
200            case 48000:
201            case 24000:
202            case 12000:
203                fscode = 1;
204                break;
205            default:
206            case 44100:
207            case 22050:
208            case 11025:
209                fscode = 2;
210                break;
211            case 32000:
212            case 16000:
213            case 8000:
214                fscode = 3;
215            }
216            avio_wb16(s, fscode); /* codec additional info, for AC-3, seems
217                                     to be a frequency code */
218            /* special hack to compensate rounding errors... */
219            if (coded_frame_size == 557)
220                coded_frame_size--;
221            avio_wb32(s, coded_frame_size); /* frame length */
222            avio_wb32(s, 0x51540); /* unknown */
223            avio_wb32(s, stream->par->bit_rate / 8 * 60); /* bytes per minute */
224            avio_wb32(s, stream->par->bit_rate / 8 * 60); /* bytes per minute */
225            avio_wb16(s, 0x01);
226            /* frame length : seems to be very important */
227            avio_wb16(s, coded_frame_size);
228            avio_wb32(s, 0); /* unknown */
229            avio_wb16(s, stream->par->sample_rate); /* sample rate */
230            avio_wb32(s, 0x10); /* unknown */
231            avio_wb16(s, stream->par->ch_layout.nb_channels);
232            put_str8(s, "Int0"); /* codec name */
233            if (stream->par->codec_tag) {
234                avio_w8(s, 4); /* tag length */
235                avio_wl32(s, stream->par->codec_tag);
236            } else {
237                av_log(ctx, AV_LOG_ERROR, "Invalid codec tag\n");
238                return -1;
239            }
240            avio_wb16(s, 0); /* title length */
241            avio_wb16(s, 0); /* author length */
242            avio_wb16(s, 0); /* copyright length */
243            avio_w8(s, 0); /* end of header */
244        } else {
245            /* video codec info */
246            avio_wb32(s,34); /* size */
247            ffio_wfourcc(s, "VIDO");
248            if(stream->par->codec_id == AV_CODEC_ID_RV10)
249                ffio_wfourcc(s,"RV10");
250            else
251                ffio_wfourcc(s,"RV20");
252            avio_wb16(s, stream->par->width);
253            avio_wb16(s, stream->par->height);
254
255            if (stream->frame_rate.num / stream->frame_rate.den > 65535) {
256                av_log(s, AV_LOG_ERROR, "Frame rate %d is too high\n", stream->frame_rate.num / stream->frame_rate.den);
257                return AVERROR(EINVAL);
258            }
259
260            avio_wb16(s, stream->frame_rate.num / stream->frame_rate.den); /* frames per seconds ? */
261            avio_wb32(s,0);     /* unknown meaning */
262            avio_wb16(s, stream->frame_rate.num / stream->frame_rate.den);  /* unknown meaning */
263            avio_wb32(s,0);     /* unknown meaning */
264            avio_wb16(s, 8);    /* unknown meaning */
265            /* Seems to be the codec version: only use basic H.263. The next
266               versions seems to add a differential DC coding as in
267               MPEG... nothing new under the sun. */
268            if(stream->par->codec_id == AV_CODEC_ID_RV10)
269                avio_wb32(s,0x10000000);
270            else
271                avio_wb32(s,0x20103001);
272            //avio_wb32(s,0x10003000);
273        }
274    }
275
276    /* patch data offset field */
277    rm->data_pos = avio_tell(s);
278    if (avio_seek(s, data_offset, SEEK_SET) >= 0) {
279        avio_wb32(s, rm->data_pos);
280        avio_seek(s, rm->data_pos, SEEK_SET);
281    }
282
283    /* data stream */
284    ffio_wfourcc(s, "DATA");
285    avio_wb32(s,data_size + 10 + 8);
286    avio_wb16(s,0);
287
288    avio_wb32(s, nb_packets); /* number of packets */
289    avio_wb32(s,0); /* next data header */
290    return 0;
291}
292
293static void write_packet_header(AVFormatContext *ctx, StreamInfo *stream,
294                                int length, int key_frame)
295{
296    int timestamp;
297    AVIOContext *s = ctx->pb;
298
299    stream->nb_packets++;
300    stream->packet_total_size += length;
301    if (length > stream->packet_max_size)
302        stream->packet_max_size =  length;
303
304    avio_wb16(s,0); /* version */
305    avio_wb16(s,length + 12);
306    avio_wb16(s, stream->num); /* stream number */
307    timestamp = av_rescale_q_rnd(stream->nb_frames, (AVRational){1000, 1}, stream->frame_rate, AV_ROUND_ZERO);
308    avio_wb32(s, timestamp); /* timestamp */
309    avio_w8(s, 0); /* reserved */
310    avio_w8(s, key_frame ? 2 : 0); /* flags */
311}
312
313static int rm_write_header(AVFormatContext *s)
314{
315    RMMuxContext *rm = s->priv_data;
316    StreamInfo *stream;
317    int n;
318    AVCodecParameters *par;
319
320    if (s->nb_streams > 2) {
321        av_log(s, AV_LOG_ERROR, "At most 2 streams are currently supported for muxing in RM\n");
322        return AVERROR_PATCHWELCOME;
323    }
324
325    for(n=0;n<s->nb_streams;n++) {
326        AVStream *st = s->streams[n];
327        int frame_size;
328
329        s->streams[n]->id = n;
330        par = s->streams[n]->codecpar;
331        stream = &rm->streams[n];
332        memset(stream, 0, sizeof(StreamInfo));
333        stream->num = n;
334        stream->bit_rate = par->bit_rate;
335        stream->par = par;
336
337        switch (par->codec_type) {
338        case AVMEDIA_TYPE_AUDIO:
339            rm->audio_stream = stream;
340            frame_size = av_get_audio_frame_duration2(par, 0);
341            stream->frame_rate = (AVRational){par->sample_rate, frame_size};
342            /* XXX: dummy values */
343            stream->packet_max_size = 1024;
344            stream->nb_packets = 0;
345            stream->total_frames = stream->nb_packets;
346            break;
347        case AVMEDIA_TYPE_VIDEO:
348            rm->video_stream = stream;
349            // TODO: should be avg_frame_rate
350            stream->frame_rate = av_inv_q(st->time_base);
351            /* XXX: dummy values */
352            stream->packet_max_size = 4096;
353            stream->nb_packets = 0;
354            stream->total_frames = stream->nb_packets;
355            break;
356        default:
357            return -1;
358        }
359    }
360
361    if (rv10_write_header(s, 0, 0))
362        return AVERROR_INVALIDDATA;
363    return 0;
364}
365
366static int rm_write_audio(AVFormatContext *s, const uint8_t *buf, int size, int flags)
367{
368    RMMuxContext *rm = s->priv_data;
369    AVIOContext *pb = s->pb;
370    StreamInfo *stream = rm->audio_stream;
371    int i;
372
373    write_packet_header(s, stream, size, !!(flags & AV_PKT_FLAG_KEY));
374
375    if (stream->par->codec_id == AV_CODEC_ID_AC3) {
376        /* for AC-3, the words seem to be reversed */
377        for (i = 0; i < size; i += 2) {
378            avio_w8(pb, buf[i + 1]);
379            avio_w8(pb, buf[i]);
380        }
381    } else {
382        avio_write(pb, buf, size);
383    }
384    stream->nb_frames++;
385    return 0;
386}
387
388static int rm_write_video(AVFormatContext *s, const uint8_t *buf, int size, int flags)
389{
390    RMMuxContext *rm = s->priv_data;
391    AVIOContext *pb = s->pb;
392    StreamInfo *stream = rm->video_stream;
393    int key_frame = !!(flags & AV_PKT_FLAG_KEY);
394
395    /* XXX: this is incorrect: should be a parameter */
396
397    /* Well, I spent some time finding the meaning of these bits. I am
398       not sure I understood everything, but it works !! */
399    if (size > MAX_PACKET_SIZE) {
400        av_log(s, AV_LOG_ERROR, "Muxing packets larger than 64 kB (%d) is not supported\n", size);
401        return AVERROR_PATCHWELCOME;
402    }
403    write_packet_header(s, stream, size + 7 + (size >= 0x4000)*4, key_frame);
404    /* bit 7: '1' if final packet of a frame converted in several packets */
405    avio_w8(pb, 0x81);
406    /* bit 7: '1' if I-frame. bits 6..0 : sequence number in current
407       frame starting from 1 */
408    if (key_frame) {
409        avio_w8(pb, 0x81);
410    } else {
411        avio_w8(pb, 0x01);
412    }
413    if(size >= 0x4000){
414        avio_wb32(pb, size); /* total frame size */
415        avio_wb32(pb, size); /* offset from the start or the end */
416    }else{
417        avio_wb16(pb, 0x4000 | size); /* total frame size */
418        avio_wb16(pb, 0x4000 | size); /* offset from the start or the end */
419    }
420    avio_w8(pb, stream->nb_frames & 0xff);
421
422    avio_write(pb, buf, size);
423
424    stream->nb_frames++;
425    return 0;
426}
427
428static int rm_write_packet(AVFormatContext *s, AVPacket *pkt)
429{
430    if (s->streams[pkt->stream_index]->codecpar->codec_type ==
431        AVMEDIA_TYPE_AUDIO)
432        return rm_write_audio(s, pkt->data, pkt->size, pkt->flags);
433    else
434        return rm_write_video(s, pkt->data, pkt->size, pkt->flags);
435}
436
437static int rm_write_trailer(AVFormatContext *s)
438{
439    RMMuxContext *rm = s->priv_data;
440    int data_size, index_pos, i;
441    AVIOContext *pb = s->pb;
442
443    if (s->pb->seekable & AVIO_SEEKABLE_NORMAL) {
444        /* end of file: finish to write header */
445        index_pos = avio_tell(pb);
446        data_size = index_pos - rm->data_pos;
447
448        /* FIXME: write index */
449
450        /* undocumented end header */
451        avio_wb32(pb, 0);
452        avio_wb32(pb, 0);
453
454        avio_seek(pb, 0, SEEK_SET);
455        for(i=0;i<s->nb_streams;i++)
456            rm->streams[i].total_frames = rm->streams[i].nb_frames;
457        rv10_write_header(s, data_size, 0);
458    } else {
459        /* undocumented end header */
460        avio_wb32(pb, 0);
461        avio_wb32(pb, 0);
462    }
463
464    return 0;
465}
466
467
468const AVOutputFormat ff_rm_muxer = {
469    .name              = "rm",
470    .long_name         = NULL_IF_CONFIG_SMALL("RealMedia"),
471    .mime_type         = "application/vnd.rn-realmedia",
472    .extensions        = "rm,ra",
473    .priv_data_size    = sizeof(RMMuxContext),
474    .audio_codec       = AV_CODEC_ID_AC3,
475    .video_codec       = AV_CODEC_ID_RV10,
476    .write_header      = rm_write_header,
477    .write_packet      = rm_write_packet,
478    .write_trailer     = rm_write_trailer,
479    .codec_tag         = (const AVCodecTag* const []){ ff_rm_codec_tags, 0 },
480};
481