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ffmpeg/libavformat/rmenc.c

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/*
* "Real" compatible muxer.
* Copyright (c) 2000, 2001 Fabrice Bellard
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avformat.h"
#include "avio_internal.h"
#include "rm.h"
#include "libavutil/dict.h"
typedef struct StreamInfo {
int nb_packets;
int packet_total_size;
int packet_max_size;
/* codec related output */
int bit_rate;
AVRational frame_rate;
int nb_frames; /* current frame number */
int total_frames; /* total number of frames */
int num;
AVCodecParameters *par;
} StreamInfo;
typedef struct RMMuxContext {
StreamInfo streams[2];
StreamInfo *audio_stream, *video_stream;
int data_pos; /* position of the data after the header */
} RMMuxContext;
/* in ms */
#define BUFFER_DURATION 0
/* the header needs at most 7 + 4 + 12 B */
#define MAX_HEADER_SIZE (7 + 4 + 12)
/* UINT16_MAX is the maximal chunk size */
#define MAX_PACKET_SIZE (UINT16_MAX - MAX_HEADER_SIZE)
static void put_str(AVIOContext *s, const char *tag)
{
avio_wb16(s,strlen(tag));
while (*tag) {
avio_w8(s, *tag++);
}
}
static void put_str8(AVIOContext *s, const char *tag)
{
avio_w8(s, strlen(tag));
while (*tag) {
avio_w8(s, *tag++);
}
}
static int rv10_write_header(AVFormatContext *ctx,
int data_size, int index_pos)
{
RMMuxContext *rm = ctx->priv_data;
AVIOContext *s = ctx->pb;
StreamInfo *stream;
const char *desc, *mimetype;
int nb_packets, packet_total_size, packet_max_size, size, packet_avg_size, i;
int bit_rate, v, duration, flags;
int data_offset;
AVDictionaryEntry *tag;
ffio_wfourcc(s, ".RMF");
avio_wb32(s,18); /* header size */
avio_wb16(s,0);
avio_wb32(s,0);
avio_wb32(s,4 + ctx->nb_streams); /* num headers */
ffio_wfourcc(s,"PROP");
avio_wb32(s, 50);
avio_wb16(s, 0);
packet_max_size = 0;
packet_total_size = 0;
nb_packets = 0;
bit_rate = 0;
duration = 0;
for(i=0;i<ctx->nb_streams;i++) {
StreamInfo *stream = &rm->streams[i];
bit_rate += stream->bit_rate;
if (stream->packet_max_size > packet_max_size)
packet_max_size = stream->packet_max_size;
nb_packets += stream->nb_packets;
packet_total_size += stream->packet_total_size;
/* select maximum duration */
v = av_rescale_q_rnd(stream->total_frames, (AVRational){1000, 1}, stream->frame_rate, AV_ROUND_ZERO);
if (v > duration)
duration = v;
}
avio_wb32(s, bit_rate); /* max bit rate */
avio_wb32(s, bit_rate); /* avg bit rate */
avio_wb32(s, packet_max_size); /* max packet size */
if (nb_packets > 0)
packet_avg_size = packet_total_size / nb_packets;
else
packet_avg_size = 0;
avio_wb32(s, packet_avg_size); /* avg packet size */
avio_wb32(s, nb_packets); /* num packets */
avio_wb32(s, duration); /* duration */
avio_wb32(s, BUFFER_DURATION); /* preroll */
avio_wb32(s, index_pos); /* index offset */
/* computation of data the data offset */
data_offset = avio_tell(s);
avio_wb32(s, 0); /* data offset : will be patched after */
avio_wb16(s, ctx->nb_streams); /* num streams */
flags = 1 | 2; /* save allowed & perfect play */
if (!(s->seekable & AVIO_SEEKABLE_NORMAL))
flags |= 4; /* live broadcast */
avio_wb16(s, flags);
/* comments */
ffio_wfourcc(s,"CONT");
size = 4 * 2 + 10;
for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) {
tag = av_dict_get(ctx->metadata, ff_rm_metadata[i], NULL, 0);
if(tag) size += strlen(tag->value);
}
avio_wb32(s,size);
avio_wb16(s,0);
for(i=0; i<FF_ARRAY_ELEMS(ff_rm_metadata); i++) {
tag = av_dict_get(ctx->metadata, ff_rm_metadata[i], NULL, 0);
put_str(s, tag ? tag->value : "");
}
for(i=0;i<ctx->nb_streams;i++) {
int codec_data_size;
stream = &rm->streams[i];
if (stream->par->codec_type == AVMEDIA_TYPE_AUDIO) {
desc = "The Audio Stream";
mimetype = "audio/x-pn-realaudio";
codec_data_size = 73;
} else {
desc = "The Video Stream";
mimetype = "video/x-pn-realvideo";
codec_data_size = 34;
}
ffio_wfourcc(s,"MDPR");
size = 10 + 9 * 4 + strlen(desc) + strlen(mimetype) + codec_data_size;
avio_wb32(s, size);
avio_wb16(s, 0);
avio_wb16(s, i); /* stream number */
avio_wb32(s, stream->bit_rate); /* max bit rate */
avio_wb32(s, stream->bit_rate); /* avg bit rate */
avio_wb32(s, stream->packet_max_size); /* max packet size */
if (stream->nb_packets > 0)
packet_avg_size = stream->packet_total_size /
stream->nb_packets;
else
packet_avg_size = 0;
avio_wb32(s, packet_avg_size); /* avg packet size */
avio_wb32(s, 0); /* start time */
avio_wb32(s, BUFFER_DURATION); /* preroll */
/* duration */
if (!(s->seekable & AVIO_SEEKABLE_NORMAL) || !stream->total_frames)
avio_wb32(s, (int)(3600 * 1000));
else
avio_wb32(s, av_rescale_q_rnd(stream->total_frames, (AVRational){1000, 1}, stream->frame_rate, AV_ROUND_ZERO));
put_str8(s, desc);
put_str8(s, mimetype);
avio_wb32(s, codec_data_size);
if (stream->par->codec_type == AVMEDIA_TYPE_AUDIO) {
int coded_frame_size, fscode, sample_rate;
int frame_size = av_get_audio_frame_duration2(stream->par, 0);
sample_rate = stream->par->sample_rate;
coded_frame_size = (stream->par->bit_rate *
frame_size) / (8 * sample_rate);
/* audio codec info */
avio_write(s, ".ra", 3);
avio_w8(s, 0xfd);
avio_wb32(s, 0x00040000); /* version */
ffio_wfourcc(s, ".ra4");
avio_wb32(s, 0x01b53530); /* stream length */
avio_wb16(s, 4); /* unknown */
avio_wb32(s, 0x39); /* header size */
switch(sample_rate) {
case 48000:
case 24000:
case 12000:
fscode = 1;
break;
default:
case 44100:
case 22050:
case 11025:
fscode = 2;
break;
case 32000:
case 16000:
case 8000:
fscode = 3;
}
avio_wb16(s, fscode); /* codec additional info, for AC-3, seems
to be a frequency code */
/* special hack to compensate rounding errors... */
if (coded_frame_size == 557)
coded_frame_size--;
avio_wb32(s, coded_frame_size); /* frame length */
avio_wb32(s, 0x51540); /* unknown */
avio_wb32(s, stream->par->bit_rate / 8 * 60); /* bytes per minute */
avio_wb32(s, stream->par->bit_rate / 8 * 60); /* bytes per minute */
avio_wb16(s, 0x01);
/* frame length : seems to be very important */
avio_wb16(s, coded_frame_size);
avio_wb32(s, 0); /* unknown */
avio_wb16(s, stream->par->sample_rate); /* sample rate */
avio_wb32(s, 0x10); /* unknown */
avio_wb16(s, stream->par->ch_layout.nb_channels);
put_str8(s, "Int0"); /* codec name */
if (stream->par->codec_tag) {
avio_w8(s, 4); /* tag length */
avio_wl32(s, stream->par->codec_tag);
} else {
av_log(ctx, AV_LOG_ERROR, "Invalid codec tag\n");
return -1;
}
avio_wb16(s, 0); /* title length */
avio_wb16(s, 0); /* author length */
avio_wb16(s, 0); /* copyright length */
avio_w8(s, 0); /* end of header */
} else {
/* video codec info */
avio_wb32(s,34); /* size */
ffio_wfourcc(s, "VIDO");
if(stream->par->codec_id == AV_CODEC_ID_RV10)
ffio_wfourcc(s,"RV10");
else
ffio_wfourcc(s,"RV20");
avio_wb16(s, stream->par->width);
avio_wb16(s, stream->par->height);
if (stream->frame_rate.num / stream->frame_rate.den > 65535) {
av_log(s, AV_LOG_ERROR, "Frame rate %d is too high\n", stream->frame_rate.num / stream->frame_rate.den);
return AVERROR(EINVAL);
}
avio_wb16(s, stream->frame_rate.num / stream->frame_rate.den); /* frames per seconds ? */
avio_wb32(s,0); /* unknown meaning */
avio_wb16(s, stream->frame_rate.num / stream->frame_rate.den); /* unknown meaning */
avio_wb32(s,0); /* unknown meaning */
avio_wb16(s, 8); /* unknown meaning */
/* Seems to be the codec version: only use basic H.263. The next
versions seems to add a differential DC coding as in
MPEG... nothing new under the sun. */
if(stream->par->codec_id == AV_CODEC_ID_RV10)
avio_wb32(s,0x10000000);
else
avio_wb32(s,0x20103001);
//avio_wb32(s,0x10003000);
}
}
/* patch data offset field */
rm->data_pos = avio_tell(s);
if (avio_seek(s, data_offset, SEEK_SET) >= 0) {
avio_wb32(s, rm->data_pos);
avio_seek(s, rm->data_pos, SEEK_SET);
}
/* data stream */
ffio_wfourcc(s, "DATA");
avio_wb32(s,data_size + 10 + 8);
avio_wb16(s,0);
avio_wb32(s, nb_packets); /* number of packets */
avio_wb32(s,0); /* next data header */
return 0;
}
static void write_packet_header(AVFormatContext *ctx, StreamInfo *stream,
int length, int key_frame)
{
int timestamp;
AVIOContext *s = ctx->pb;
stream->nb_packets++;
stream->packet_total_size += length;
if (length > stream->packet_max_size)
stream->packet_max_size = length;
avio_wb16(s,0); /* version */
avio_wb16(s,length + 12);
avio_wb16(s, stream->num); /* stream number */
timestamp = av_rescale_q_rnd(stream->nb_frames, (AVRational){1000, 1}, stream->frame_rate, AV_ROUND_ZERO);
avio_wb32(s, timestamp); /* timestamp */
avio_w8(s, 0); /* reserved */
avio_w8(s, key_frame ? 2 : 0); /* flags */
}
static int rm_write_header(AVFormatContext *s)
{
RMMuxContext *rm = s->priv_data;
StreamInfo *stream;
int n;
AVCodecParameters *par;
if (s->nb_streams > 2) {
av_log(s, AV_LOG_ERROR, "At most 2 streams are currently supported for muxing in RM\n");
return AVERROR_PATCHWELCOME;
}
for(n=0;n<s->nb_streams;n++) {
AVStream *st = s->streams[n];
int frame_size;
s->streams[n]->id = n;
par = s->streams[n]->codecpar;
stream = &rm->streams[n];
memset(stream, 0, sizeof(StreamInfo));
stream->num = n;
stream->bit_rate = par->bit_rate;
stream->par = par;
switch (par->codec_type) {
case AVMEDIA_TYPE_AUDIO:
rm->audio_stream = stream;
frame_size = av_get_audio_frame_duration2(par, 0);
stream->frame_rate = (AVRational){par->sample_rate, frame_size};
/* XXX: dummy values */
stream->packet_max_size = 1024;
stream->nb_packets = 0;
stream->total_frames = stream->nb_packets;
break;
case AVMEDIA_TYPE_VIDEO:
rm->video_stream = stream;
// TODO: should be avg_frame_rate
stream->frame_rate = av_inv_q(st->time_base);
/* XXX: dummy values */
stream->packet_max_size = 4096;
stream->nb_packets = 0;
stream->total_frames = stream->nb_packets;
break;
default:
return -1;
}
}
if (rv10_write_header(s, 0, 0))
return AVERROR_INVALIDDATA;
return 0;
}
static int rm_write_audio(AVFormatContext *s, const uint8_t *buf, int size, int flags)
{
RMMuxContext *rm = s->priv_data;
AVIOContext *pb = s->pb;
StreamInfo *stream = rm->audio_stream;
int i;
write_packet_header(s, stream, size, !!(flags & AV_PKT_FLAG_KEY));
if (stream->par->codec_id == AV_CODEC_ID_AC3) {
/* for AC-3, the words seem to be reversed */
for (i = 0; i < size; i += 2) {
avio_w8(pb, buf[i + 1]);
avio_w8(pb, buf[i]);
}
} else {
avio_write(pb, buf, size);
}
stream->nb_frames++;
return 0;
}
static int rm_write_video(AVFormatContext *s, const uint8_t *buf, int size, int flags)
{
RMMuxContext *rm = s->priv_data;
AVIOContext *pb = s->pb;
StreamInfo *stream = rm->video_stream;
int key_frame = !!(flags & AV_PKT_FLAG_KEY);
/* XXX: this is incorrect: should be a parameter */
/* Well, I spent some time finding the meaning of these bits. I am
not sure I understood everything, but it works !! */
if (size > MAX_PACKET_SIZE) {
av_log(s, AV_LOG_ERROR, "Muxing packets larger than 64 kB (%d) is not supported\n", size);
return AVERROR_PATCHWELCOME;
}
write_packet_header(s, stream, size + 7 + (size >= 0x4000)*4, key_frame);
/* bit 7: '1' if final packet of a frame converted in several packets */
avio_w8(pb, 0x81);
/* bit 7: '1' if I-frame. bits 6..0 : sequence number in current
frame starting from 1 */
if (key_frame) {
avio_w8(pb, 0x81);
} else {
avio_w8(pb, 0x01);
}
if(size >= 0x4000){
avio_wb32(pb, size); /* total frame size */
avio_wb32(pb, size); /* offset from the start or the end */
}else{
avio_wb16(pb, 0x4000 | size); /* total frame size */
avio_wb16(pb, 0x4000 | size); /* offset from the start or the end */
}
avio_w8(pb, stream->nb_frames & 0xff);
avio_write(pb, buf, size);
stream->nb_frames++;
return 0;
}
static int rm_write_packet(AVFormatContext *s, AVPacket *pkt)
{
if (s->streams[pkt->stream_index]->codecpar->codec_type ==
AVMEDIA_TYPE_AUDIO)
return rm_write_audio(s, pkt->data, pkt->size, pkt->flags);
else
return rm_write_video(s, pkt->data, pkt->size, pkt->flags);
}
static int rm_write_trailer(AVFormatContext *s)
{
RMMuxContext *rm = s->priv_data;
int data_size, index_pos, i;
AVIOContext *pb = s->pb;
if (s->pb->seekable & AVIO_SEEKABLE_NORMAL) {
/* end of file: finish to write header */
index_pos = avio_tell(pb);
data_size = index_pos - rm->data_pos;
/* FIXME: write index */
/* undocumented end header */
avio_wb32(pb, 0);
avio_wb32(pb, 0);
avio_seek(pb, 0, SEEK_SET);
for(i=0;i<s->nb_streams;i++)
rm->streams[i].total_frames = rm->streams[i].nb_frames;
rv10_write_header(s, data_size, 0);
} else {
/* undocumented end header */
avio_wb32(pb, 0);
avio_wb32(pb, 0);
}
return 0;
}
const AVOutputFormat ff_rm_muxer = {
.name = "rm",
.long_name = NULL_IF_CONFIG_SMALL("RealMedia"),
.mime_type = "application/vnd.rn-realmedia",
.extensions = "rm,ra",
.priv_data_size = sizeof(RMMuxContext),
.audio_codec = AV_CODEC_ID_AC3,
.video_codec = AV_CODEC_ID_RV10,
.write_header = rm_write_header,
.write_packet = rm_write_packet,
.write_trailer = rm_write_trailer,
.codec_tag = (const AVCodecTag* const []){ ff_rm_codec_tags, 0 },
};
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