FFmpeg/libavformat/rmenc.c
Clément Bœsch 7308439158 lavf: Don't explicitly flush after each written packet in muxers
Since 596e5d4783, this is not necessary anymore. It also allows to
actually disable the flushing, improving write performance (but
possibly giving worse latency in real-time streaming).

Signed-off-by: Martin Storsjö <martin@martin.st>
2013-09-16 22:17:33 +03:00

479 lines
16 KiB
C

/*
* "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 {
int nb_packets;
int packet_total_size;
int packet_max_size;
/* codec related output */
int bit_rate;
float frame_rate;
int nb_frames; /* current frame number */
int total_frames; /* total number of frames */
int num;
AVCodecContext *enc;
} StreamInfo;
typedef struct {
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
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;
unsigned char *data_offset_ptr, *start_ptr;
const char *desc, *mimetype;
int nb_packets, packet_total_size, packet_max_size, size, packet_avg_size, i;
int bit_rate, v, duration, flags, data_pos;
AVDictionaryEntry *tag;
start_ptr = s->buf_ptr;
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 = (int) (1000.0 * (float)stream->total_frames / stream->frame_rate);
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_ptr = s->buf_ptr;
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)
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->enc->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 || !stream->total_frames)
avio_wb32(s, (int)(3600 * 1000));
else
avio_wb32(s, (int)(stream->total_frames * 1000 / stream->frame_rate));
put_str8(s, desc);
put_str8(s, mimetype);
avio_wb32(s, codec_data_size);
if (stream->enc->codec_type == AVMEDIA_TYPE_AUDIO) {
int coded_frame_size, fscode, sample_rate;
sample_rate = stream->enc->sample_rate;
coded_frame_size = (stream->enc->bit_rate *
stream->enc->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->enc->bit_rate / 8 * 60); /* bytes per minute */
avio_wb32(s, stream->enc->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->enc->sample_rate); /* sample rate */
avio_wb32(s, 0x10); /* unknown */
avio_wb16(s, stream->enc->channels);
put_str8(s, "Int0"); /* codec name */
if (stream->enc->codec_tag) {
avio_w8(s, 4); /* tag length */
avio_wl32(s, stream->enc->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->enc->codec_id == AV_CODEC_ID_RV10)
ffio_wfourcc(s,"RV10");
else
ffio_wfourcc(s,"RV20");
avio_wb16(s, stream->enc->width);
avio_wb16(s, stream->enc->height);
avio_wb16(s, (int) stream->frame_rate); /* frames per seconds ? */
avio_wb32(s,0); /* unknown meaning */
avio_wb16(s, (int) stream->frame_rate); /* unknown meaning */
avio_wb32(s,0); /* unknown meaning */
avio_wb16(s, 8); /* unknown meaning */
/* Seems to be the codec version: only use basic H263. The next
versions seems to add a diffential DC coding as in
MPEG... nothing new under the sun */
if(stream->enc->codec_id == AV_CODEC_ID_RV10)
avio_wb32(s,0x10000000);
else
avio_wb32(s,0x20103001);
//avio_wb32(s,0x10003000);
}
}
/* patch data offset field */
data_pos = s->buf_ptr - start_ptr;
rm->data_pos = data_pos;
data_offset_ptr[0] = data_pos >> 24;
data_offset_ptr[1] = data_pos >> 16;
data_offset_ptr[2] = data_pos >> 8;
data_offset_ptr[3] = data_pos;
/* 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 = (1000 * (float)stream->nb_frames) / stream->frame_rate;
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;
AVCodecContext *codec;
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++) {
s->streams[n]->id = n;
codec = s->streams[n]->codec;
stream = &rm->streams[n];
memset(stream, 0, sizeof(StreamInfo));
stream->num = n;
stream->bit_rate = codec->bit_rate;
stream->enc = codec;
switch(codec->codec_type) {
case AVMEDIA_TYPE_AUDIO:
rm->audio_stream = stream;
stream->frame_rate = (float)codec->sample_rate / (float)codec->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;
stream->frame_rate = (float)codec->time_base.den / (float)codec->time_base.num;
/* 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;
avio_flush(s->pb);
return 0;
}
static int rm_write_audio(AVFormatContext *s, const uint8_t *buf, int size, int flags)
{
uint8_t *buf1;
RMMuxContext *rm = s->priv_data;
AVIOContext *pb = s->pb;
StreamInfo *stream = rm->audio_stream;
int i;
/* XXX: suppress this malloc */
buf1 = av_malloc(size * sizeof(uint8_t));
write_packet_header(s, stream, size, !!(flags & AV_PKT_FLAG_KEY));
if (stream->enc->codec_id == AV_CODEC_ID_AC3) {
/* for AC-3, the words seem to be reversed */
for(i=0;i<size;i+=2) {
buf1[i] = buf[i+1];
buf1[i+1] = buf[i];
}
avio_write(pb, buf1, size);
} else {
avio_write(pb, buf, size);
}
stream->nb_frames++;
av_free(buf1);
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 1
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 */
}
#else
/* full frame */
write_packet_header(s, size + 6);
avio_w8(pb, 0xc0);
avio_wb16(pb, 0x4000 + size); /* total frame size */
avio_wb16(pb, 0x4000 + packet_number * 126); /* position in stream */
#endif
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]->codec->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) {
/* 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;
}
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 },
};