FFmpeg: libavformat/ffmenc.c Source File

00001 /*
00002  * FFM (ffserver live feed) muxer
00003  * Copyright (c) 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 
00022 #include "libavutil/intreadwrite.h"
00023 #include "libavutil/intfloat.h"
00024 #include "libavutil/avassert.h"
00025 #include "avformat.h"
00026 #include "internal.h"
00027 #include "ffm.h"
00028 
00029 static void flush_packet(AVFormatContext *s)
00030 {
00031     FFMContext *ffm = s->priv_data;
00032     int fill_size, h;
00033     AVIOContext *pb = s->pb;
00034 
00035     fill_size = ffm->packet_end - ffm->packet_ptr;
00036     memset(ffm->packet_ptr, 0, fill_size);
00037 
00038     av_assert1(avio_tell(pb) % ffm->packet_size == 0);
00039 
00040     /* put header */
00041     avio_wb16(pb, PACKET_ID);
00042     avio_wb16(pb, fill_size);
00043     avio_wb64(pb, ffm->dts);
00044     h = ffm->frame_offset;
00045     if (ffm->first_packet)
00046         h |= 0x8000;
00047     avio_wb16(pb, h);
00048     avio_write(pb, ffm->packet, ffm->packet_end - ffm->packet);
00049     avio_flush(pb);
00050 
00051     /* prepare next packet */
00052     ffm->frame_offset = 0; /* no key frame */
00053     ffm->packet_ptr = ffm->packet;
00054     ffm->first_packet = 0;
00055 }
00056 
00057 /* 'first' is true if first data of a frame */
00058 static void ffm_write_data(AVFormatContext *s,
00059                            const uint8_t *buf, int size,
00060                            int64_t dts, int header)
00061 {
00062     FFMContext *ffm = s->priv_data;
00063     int len;
00064 
00065     if (header && ffm->frame_offset == 0) {
00066         ffm->frame_offset = ffm->packet_ptr - ffm->packet + FFM_HEADER_SIZE;
00067         ffm->dts = dts;
00068     }
00069 
00070     /* write as many packets as needed */
00071     while (size > 0) {
00072         len = ffm->packet_end - ffm->packet_ptr;
00073         if (len > size)
00074             len = size;
00075         memcpy(ffm->packet_ptr, buf, len);
00076 
00077         ffm->packet_ptr += len;
00078         buf += len;
00079         size -= len;
00080         if (ffm->packet_ptr >= ffm->packet_end)
00081             flush_packet(s);
00082     }
00083 }
00084 
00085 static int ffm_write_header(AVFormatContext *s)
00086 {
00087     FFMContext *ffm = s->priv_data;
00088     AVStream *st;
00089     AVIOContext *pb = s->pb;
00090     AVCodecContext *codec;
00091     int bit_rate, i;
00092 
00093     ffm->packet_size = FFM_PACKET_SIZE;
00094 
00095     /* header */
00096     avio_wl32(pb, MKTAG('F', 'F', 'M', '1'));
00097     avio_wb32(pb, ffm->packet_size);
00098     avio_wb64(pb, 0); /* current write position */
00099 
00100     avio_wb32(pb, s->nb_streams);
00101     bit_rate = 0;
00102     for(i=0;i<s->nb_streams;i++) {
00103         st = s->streams[i];
00104         bit_rate += st->codec->bit_rate;
00105     }
00106     avio_wb32(pb, bit_rate);
00107 
00108     /* list of streams */
00109     for(i=0;i<s->nb_streams;i++) {
00110         st = s->streams[i];
00111         avpriv_set_pts_info(st, 64, 1, 1000000);
00112 
00113         codec = st->codec;
00114         /* generic info */
00115         avio_wb32(pb, codec->codec_id);
00116         avio_w8(pb, codec->codec_type);
00117         avio_wb32(pb, codec->bit_rate);
00118         avio_wb32(pb, codec->flags);
00119         avio_wb32(pb, codec->flags2);
00120         avio_wb32(pb, codec->debug);
00121         /* specific info */
00122         switch(codec->codec_type) {
00123         case AVMEDIA_TYPE_VIDEO:
00124             avio_wb32(pb, codec->time_base.num);
00125             avio_wb32(pb, codec->time_base.den);
00126             avio_wb16(pb, codec->width);
00127             avio_wb16(pb, codec->height);
00128             avio_wb16(pb, codec->gop_size);
00129             avio_wb32(pb, codec->pix_fmt);
00130             avio_w8(pb, codec->qmin);
00131             avio_w8(pb, codec->qmax);
00132             avio_w8(pb, codec->max_qdiff);
00133             avio_wb16(pb, (int) (codec->qcompress * 10000.0));
00134             avio_wb16(pb, (int) (codec->qblur * 10000.0));
00135             avio_wb32(pb, codec->bit_rate_tolerance);
00136             avio_put_str(pb, codec->rc_eq ? codec->rc_eq : "tex^qComp");
00137             avio_wb32(pb, codec->rc_max_rate);
00138             avio_wb32(pb, codec->rc_min_rate);
00139             avio_wb32(pb, codec->rc_buffer_size);
00140             avio_wb64(pb, av_double2int(codec->i_quant_factor));
00141             avio_wb64(pb, av_double2int(codec->b_quant_factor));
00142             avio_wb64(pb, av_double2int(codec->i_quant_offset));
00143             avio_wb64(pb, av_double2int(codec->b_quant_offset));
00144             avio_wb32(pb, codec->dct_algo);
00145             avio_wb32(pb, codec->strict_std_compliance);
00146             avio_wb32(pb, codec->max_b_frames);
00147             avio_wb32(pb, codec->mpeg_quant);
00148             avio_wb32(pb, codec->intra_dc_precision);
00149             avio_wb32(pb, codec->me_method);
00150             avio_wb32(pb, codec->mb_decision);
00151             avio_wb32(pb, codec->nsse_weight);
00152             avio_wb32(pb, codec->frame_skip_cmp);
00153             avio_wb64(pb, av_double2int(codec->rc_buffer_aggressivity));
00154             avio_wb32(pb, codec->codec_tag);
00155             avio_w8(pb, codec->thread_count);
00156             avio_wb32(pb, codec->coder_type);
00157             avio_wb32(pb, codec->me_cmp);
00158             avio_wb32(pb, codec->me_subpel_quality);
00159             avio_wb32(pb, codec->me_range);
00160             avio_wb32(pb, codec->keyint_min);
00161             avio_wb32(pb, codec->scenechange_threshold);
00162             avio_wb32(pb, codec->b_frame_strategy);
00163             avio_wb64(pb, av_double2int(codec->qcompress));
00164             avio_wb64(pb, av_double2int(codec->qblur));
00165             avio_wb32(pb, codec->max_qdiff);
00166             avio_wb32(pb, codec->refs);
00167             break;
00168         case AVMEDIA_TYPE_AUDIO:
00169             avio_wb32(pb, codec->sample_rate);
00170             avio_wl16(pb, codec->channels);
00171             avio_wl16(pb, codec->frame_size);
00172             avio_wl16(pb, codec->sample_fmt);
00173             break;
00174         default:
00175             return -1;
00176         }
00177         if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
00178             avio_wb32(pb, codec->extradata_size);
00179             avio_write(pb, codec->extradata, codec->extradata_size);
00180         }
00181     }
00182 
00183     /* flush until end of block reached */
00184     while ((avio_tell(pb) % ffm->packet_size) != 0)
00185         avio_w8(pb, 0);
00186 
00187     avio_flush(pb);
00188 
00189     /* init packet mux */
00190     ffm->packet_ptr = ffm->packet;
00191     ffm->packet_end = ffm->packet + ffm->packet_size - FFM_HEADER_SIZE;
00192     av_assert0(ffm->packet_end >= ffm->packet);
00193     ffm->frame_offset = 0;
00194     ffm->dts = 0;
00195     ffm->first_packet = 1;
00196 
00197     return 0;
00198 }
00199 
00200 static int ffm_write_packet(AVFormatContext *s, AVPacket *pkt)
00201 {
00202     int64_t dts;
00203     uint8_t header[FRAME_HEADER_SIZE+4];
00204     int header_size = FRAME_HEADER_SIZE;
00205 
00206     dts = pkt->dts;
00207     /* packet size & key_frame */
00208     header[0] = pkt->stream_index;
00209     header[1] = 0;
00210     if (pkt->flags & AV_PKT_FLAG_KEY)
00211         header[1] |= FLAG_KEY_FRAME;
00212     AV_WB24(header+2, pkt->size);
00213     AV_WB24(header+5, pkt->duration);
00214     AV_WB64(header+8, pkt->pts);
00215     if (pkt->pts != pkt->dts) {
00216         header[1] |= FLAG_DTS;
00217         AV_WB32(header+16, pkt->pts - pkt->dts);
00218         header_size += 4;
00219     }
00220     ffm_write_data(s, header, header_size, dts, 1);
00221     ffm_write_data(s, pkt->data, pkt->size, dts, 0);
00222 
00223     return 0;
00224 }
00225 
00226 static int ffm_write_trailer(AVFormatContext *s)
00227 {
00228     FFMContext *ffm = s->priv_data;
00229 
00230     /* flush packets */
00231     if (ffm->packet_ptr > ffm->packet)
00232         flush_packet(s);
00233 
00234     return 0;
00235 }
00236 
00237 AVOutputFormat ff_ffm_muxer = {
00238     .name              = "ffm",
00239     .long_name         = NULL_IF_CONFIG_SMALL("FFM (FFserver live feed)"),
00240     .extensions        = "ffm",
00241     .priv_data_size    = sizeof(FFMContext),
00242     .audio_codec       = AV_CODEC_ID_MP2,
00243     .video_codec       = AV_CODEC_ID_MPEG1VIDEO,
00244     .write_header      = ffm_write_header,
00245     .write_packet      = ffm_write_packet,
00246     .write_trailer     = ffm_write_trailer,
00247 };