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libavformat/ffmenc.c

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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 "avformat.h"
00024 #include "ffm.h"
00025 
00026 static void flush_packet(AVFormatContext *s)
00027 {
00028     FFMContext *ffm = s->priv_data;
00029     int fill_size, h;
00030     ByteIOContext *pb = s->pb;
00031 
00032     fill_size = ffm->packet_end - ffm->packet_ptr;
00033     memset(ffm->packet_ptr, 0, fill_size);
00034 
00035     if (url_ftell(pb) % ffm->packet_size)
00036         av_abort();
00037 
00038     /* put header */
00039     put_be16(pb, PACKET_ID);
00040     put_be16(pb, fill_size);
00041     put_be64(pb, ffm->dts);
00042     h = ffm->frame_offset;
00043     if (ffm->first_packet)
00044         h |= 0x8000;
00045     put_be16(pb, h);
00046     put_buffer(pb, ffm->packet, ffm->packet_end - ffm->packet);
00047     put_flush_packet(pb);
00048 
00049     /* prepare next packet */
00050     ffm->frame_offset = 0; /* no key frame */
00051     ffm->packet_ptr = ffm->packet;
00052     ffm->first_packet = 0;
00053 }
00054 
00055 /* 'first' is true if first data of a frame */
00056 static void ffm_write_data(AVFormatContext *s,
00057                            const uint8_t *buf, int size,
00058                            int64_t dts, int header)
00059 {
00060     FFMContext *ffm = s->priv_data;
00061     int len;
00062 
00063     if (header && ffm->frame_offset == 0) {
00064         ffm->frame_offset = ffm->packet_ptr - ffm->packet + FFM_HEADER_SIZE;
00065         ffm->dts = dts;
00066     }
00067 
00068     /* write as many packets as needed */
00069     while (size > 0) {
00070         len = ffm->packet_end - ffm->packet_ptr;
00071         if (len > size)
00072             len = size;
00073         memcpy(ffm->packet_ptr, buf, len);
00074 
00075         ffm->packet_ptr += len;
00076         buf += len;
00077         size -= len;
00078         if (ffm->packet_ptr >= ffm->packet_end)
00079             flush_packet(s);
00080     }
00081 }
00082 
00083 static int ffm_write_header(AVFormatContext *s)
00084 {
00085     FFMContext *ffm = s->priv_data;
00086     AVStream *st;
00087     ByteIOContext *pb = s->pb;
00088     AVCodecContext *codec;
00089     int bit_rate, i;
00090 
00091     ffm->packet_size = FFM_PACKET_SIZE;
00092 
00093     /* header */
00094     put_le32(pb, MKTAG('F', 'F', 'M', '1'));
00095     put_be32(pb, ffm->packet_size);
00096     /* XXX: store write position in other file ? */
00097     put_be64(pb, ffm->packet_size); /* current write position */
00098 
00099     put_be32(pb, s->nb_streams);
00100     bit_rate = 0;
00101     for(i=0;i<s->nb_streams;i++) {
00102         st = s->streams[i];
00103         bit_rate += st->codec->bit_rate;
00104     }
00105     put_be32(pb, bit_rate);
00106 
00107     /* list of streams */
00108     for(i=0;i<s->nb_streams;i++) {
00109         st = s->streams[i];
00110         av_set_pts_info(st, 64, 1, 1000000);
00111 
00112         codec = st->codec;
00113         /* generic info */
00114         put_be32(pb, codec->codec_id);
00115         put_byte(pb, codec->codec_type);
00116         put_be32(pb, codec->bit_rate);
00117         put_be32(pb, st->quality);
00118         put_be32(pb, codec->flags);
00119         put_be32(pb, codec->flags2);
00120         put_be32(pb, codec->debug);
00121         /* specific info */
00122         switch(codec->codec_type) {
00123         case CODEC_TYPE_VIDEO:
00124             put_be32(pb, codec->time_base.num);
00125             put_be32(pb, codec->time_base.den);
00126             put_be16(pb, codec->width);
00127             put_be16(pb, codec->height);
00128             put_be16(pb, codec->gop_size);
00129             put_be32(pb, codec->pix_fmt);
00130             put_byte(pb, codec->qmin);
00131             put_byte(pb, codec->qmax);
00132             put_byte(pb, codec->max_qdiff);
00133             put_be16(pb, (int) (codec->qcompress * 10000.0));
00134             put_be16(pb, (int) (codec->qblur * 10000.0));
00135             put_be32(pb, codec->bit_rate_tolerance);
00136             put_strz(pb, codec->rc_eq ? codec->rc_eq : "tex^qComp");
00137             put_be32(pb, codec->rc_max_rate);
00138             put_be32(pb, codec->rc_min_rate);
00139             put_be32(pb, codec->rc_buffer_size);
00140             put_be64(pb, av_dbl2int(codec->i_quant_factor));
00141             put_be64(pb, av_dbl2int(codec->b_quant_factor));
00142             put_be64(pb, av_dbl2int(codec->i_quant_offset));
00143             put_be64(pb, av_dbl2int(codec->b_quant_offset));
00144             put_be32(pb, codec->dct_algo);
00145             put_be32(pb, codec->strict_std_compliance);
00146             put_be32(pb, codec->max_b_frames);
00147             put_be32(pb, codec->luma_elim_threshold);
00148             put_be32(pb, codec->chroma_elim_threshold);
00149             put_be32(pb, codec->mpeg_quant);
00150             put_be32(pb, codec->intra_dc_precision);
00151             put_be32(pb, codec->me_method);
00152             put_be32(pb, codec->mb_decision);
00153             put_be32(pb, codec->nsse_weight);
00154             put_be32(pb, codec->frame_skip_cmp);
00155             put_be64(pb, av_dbl2int(codec->rc_buffer_aggressivity));
00156             put_be32(pb, codec->codec_tag);
00157             put_byte(pb, codec->thread_count);
00158             break;
00159         case CODEC_TYPE_AUDIO:
00160             put_be32(pb, codec->sample_rate);
00161             put_le16(pb, codec->channels);
00162             put_le16(pb, codec->frame_size);
00163             break;
00164         default:
00165             return -1;
00166         }
00167         if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
00168             put_be32(pb, codec->extradata_size);
00169             put_buffer(pb, codec->extradata, codec->extradata_size);
00170         }
00171     }
00172 
00173     /* flush until end of block reached */
00174     while ((url_ftell(pb) % ffm->packet_size) != 0)
00175         put_byte(pb, 0);
00176 
00177     put_flush_packet(pb);
00178 
00179     /* init packet mux */
00180     ffm->packet_ptr = ffm->packet;
00181     ffm->packet_end = ffm->packet + ffm->packet_size - FFM_HEADER_SIZE;
00182     assert(ffm->packet_end >= ffm->packet);
00183     ffm->frame_offset = 0;
00184     ffm->dts = 0;
00185     ffm->first_packet = 1;
00186 
00187     return 0;
00188 }
00189 
00190 static int ffm_write_packet(AVFormatContext *s, AVPacket *pkt)
00191 {
00192     int64_t dts;
00193     uint8_t header[FRAME_HEADER_SIZE+4];
00194     int header_size = FRAME_HEADER_SIZE;
00195 
00196     dts = s->timestamp + pkt->dts;
00197     /* packet size & key_frame */
00198     header[0] = pkt->stream_index;
00199     header[1] = 0;
00200     if (pkt->flags & PKT_FLAG_KEY)
00201         header[1] |= FLAG_KEY_FRAME;
00202     AV_WB24(header+2, pkt->size);
00203     AV_WB24(header+5, pkt->duration);
00204     AV_WB64(header+8, s->timestamp + pkt->pts);
00205     if (pkt->pts != pkt->dts) {
00206         header[1] |= FLAG_DTS;
00207         AV_WB32(header+16, pkt->pts - pkt->dts);
00208         header_size += 4;
00209     }
00210     ffm_write_data(s, header, header_size, dts, 1);
00211     ffm_write_data(s, pkt->data, pkt->size, dts, 0);
00212 
00213     return 0;
00214 }
00215 
00216 static int ffm_write_trailer(AVFormatContext *s)
00217 {
00218     ByteIOContext *pb = s->pb;
00219     FFMContext *ffm = s->priv_data;
00220 
00221     /* flush packets */
00222     if (ffm->packet_ptr > ffm->packet)
00223         flush_packet(s);
00224 
00225     put_flush_packet(pb);
00226 
00227     if (!url_is_streamed(pb)) {
00228         int64_t size;
00229         /* update the write offset */
00230         size = url_ftell(pb);
00231         url_fseek(pb, 8, SEEK_SET);
00232         put_be64(pb, size);
00233         put_flush_packet(pb);
00234     }
00235 
00236     return 0;
00237 }
00238 
00239 AVOutputFormat ffm_muxer = {
00240     "ffm",
00241     NULL_IF_CONFIG_SMALL("FFM (FFserver live feed) format"),
00242     "",
00243     "ffm",
00244     sizeof(FFMContext),
00245     /* not really used */
00246     CODEC_ID_MP2,
00247     CODEC_ID_MPEG1VIDEO,
00248     ffm_write_header,
00249     ffm_write_packet,
00250     ffm_write_trailer,
00251 };

Generated on Tue Nov 4 2014 12:59:23 for ffmpeg by  doxygen 1.7.1