yading@11: /*
yading@11:  * FFM (ffserver live feed) demuxer
yading@11:  * Copyright (c) 2001 Fabrice Bellard
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "libavutil/intreadwrite.h"
yading@11: #include "libavutil/intfloat.h"
yading@11: #include "avformat.h"
yading@11: #include "internal.h"
yading@11: #include "ffm.h"
yading@11: #include "avio_internal.h"
yading@11: 
yading@11: static int ffm_is_avail_data(AVFormatContext *s, int size)
yading@11: {
yading@11:     FFMContext *ffm = s->priv_data;
yading@11:     int64_t pos, avail_size;
yading@11:     int len;
yading@11: 
yading@11:     len = ffm->packet_end - ffm->packet_ptr;
yading@11:     if (size <= len)
yading@11:         return 1;
yading@11:     pos = avio_tell(s->pb);
yading@11:     if (!ffm->write_index) {
yading@11:         if (pos == ffm->file_size)
yading@11:             return AVERROR_EOF;
yading@11:         avail_size = ffm->file_size - pos;
yading@11:     } else {
yading@11:     if (pos == ffm->write_index) {
yading@11:         /* exactly at the end of stream */
yading@11:         return AVERROR(EAGAIN);
yading@11:     } else if (pos < ffm->write_index) {
yading@11:         avail_size = ffm->write_index - pos;
yading@11:     } else {
yading@11:         avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
yading@11:     }
yading@11:     }
yading@11:     avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
yading@11:     if (size <= avail_size)
yading@11:         return 1;
yading@11:     else
yading@11:         return AVERROR(EAGAIN);
yading@11: }
yading@11: 
yading@11: static int ffm_resync(AVFormatContext *s, int state)
yading@11: {
yading@11:     av_log(s, AV_LOG_ERROR, "resyncing\n");
yading@11:     while (state != PACKET_ID) {
yading@11:         if (url_feof(s->pb)) {
yading@11:             av_log(s, AV_LOG_ERROR, "cannot find FFM syncword\n");
yading@11:             return -1;
yading@11:         }
yading@11:         state = (state << 8) | avio_r8(s->pb);
yading@11:     }
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: /* first is true if we read the frame header */
yading@11: static int ffm_read_data(AVFormatContext *s,
yading@11:                          uint8_t *buf, int size, int header)
yading@11: {
yading@11:     FFMContext *ffm = s->priv_data;
yading@11:     AVIOContext *pb = s->pb;
yading@11:     int len, fill_size, size1, frame_offset, id;
yading@11: 
yading@11:     size1 = size;
yading@11:     while (size > 0) {
yading@11:     redo:
yading@11:         len = ffm->packet_end - ffm->packet_ptr;
yading@11:         if (len < 0)
yading@11:             return -1;
yading@11:         if (len > size)
yading@11:             len = size;
yading@11:         if (len == 0) {
yading@11:             if (avio_tell(pb) == ffm->file_size)
yading@11:                 avio_seek(pb, ffm->packet_size, SEEK_SET);
yading@11:     retry_read:
yading@11:             if (pb->buffer_size != ffm->packet_size) {
yading@11:                 int64_t tell = avio_tell(pb);
yading@11:                 ffio_set_buf_size(pb, ffm->packet_size);
yading@11:                 avio_seek(pb, tell, SEEK_SET);
yading@11:             }
yading@11:             id = avio_rb16(pb); /* PACKET_ID */
yading@11:             if (id != PACKET_ID)
yading@11:                 if (ffm_resync(s, id) < 0)
yading@11:                     return -1;
yading@11:             fill_size = avio_rb16(pb);
yading@11:             ffm->dts = avio_rb64(pb);
yading@11:             frame_offset = avio_rb16(pb);
yading@11:             avio_read(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
yading@11:             ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
yading@11:             if (ffm->packet_end < ffm->packet || frame_offset < 0)
yading@11:                 return -1;
yading@11:             /* if first packet or resynchronization packet, we must
yading@11:                handle it specifically */
yading@11:             if (ffm->first_packet || (frame_offset & 0x8000)) {
yading@11:                 if (!frame_offset) {
yading@11:                     /* This packet has no frame headers in it */
yading@11:                     if (avio_tell(pb) >= ffm->packet_size * 3LL) {
yading@11:                         avio_seek(pb, -ffm->packet_size * 2LL, SEEK_CUR);
yading@11:                         goto retry_read;
yading@11:                     }
yading@11:                     /* This is bad, we cannot find a valid frame header */
yading@11:                     return 0;
yading@11:                 }
yading@11:                 ffm->first_packet = 0;
yading@11:                 if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
yading@11:                     return -1;
yading@11:                 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
yading@11:                 if (!header)
yading@11:                     break;
yading@11:             } else {
yading@11:                 ffm->packet_ptr = ffm->packet;
yading@11:             }
yading@11:             goto redo;
yading@11:         }
yading@11:         memcpy(buf, ffm->packet_ptr, len);
yading@11:         buf += len;
yading@11:         ffm->packet_ptr += len;
yading@11:         size -= len;
yading@11:         header = 0;
yading@11:     }
yading@11:     return size1 - size;
yading@11: }
yading@11: 
yading@11: /* ensure that acutal seeking happens between FFM_PACKET_SIZE
yading@11:    and file_size - FFM_PACKET_SIZE */
yading@11: static int64_t ffm_seek1(AVFormatContext *s, int64_t pos1)
yading@11: {
yading@11:     FFMContext *ffm = s->priv_data;
yading@11:     AVIOContext *pb = s->pb;
yading@11:     int64_t pos;
yading@11: 
yading@11:     pos = FFMIN(pos1, ffm->file_size - FFM_PACKET_SIZE);
yading@11:     pos = FFMAX(pos, FFM_PACKET_SIZE);
yading@11:     av_dlog(s, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
yading@11:     return avio_seek(pb, pos, SEEK_SET);
yading@11: }
yading@11: 
yading@11: static int64_t get_dts(AVFormatContext *s, int64_t pos)
yading@11: {
yading@11:     AVIOContext *pb = s->pb;
yading@11:     int64_t dts;
yading@11: 
yading@11:     ffm_seek1(s, pos);
yading@11:     avio_skip(pb, 4);
yading@11:     dts = avio_rb64(pb);
yading@11:     av_dlog(s, "dts=%0.6f\n", dts / 1000000.0);
yading@11:     return dts;
yading@11: }
yading@11: 
yading@11: static void adjust_write_index(AVFormatContext *s)
yading@11: {
yading@11:     FFMContext *ffm = s->priv_data;
yading@11:     AVIOContext *pb = s->pb;
yading@11:     int64_t pts;
yading@11:     //int64_t orig_write_index = ffm->write_index;
yading@11:     int64_t pos_min, pos_max;
yading@11:     int64_t pts_start;
yading@11:     int64_t ptr = avio_tell(pb);
yading@11: 
yading@11: 
yading@11:     pos_min = 0;
yading@11:     pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
yading@11: 
yading@11:     pts_start = get_dts(s, pos_min);
yading@11: 
yading@11:     pts = get_dts(s, pos_max);
yading@11: 
yading@11:     if (pts - 100000 > pts_start)
yading@11:         goto end;
yading@11: 
yading@11:     ffm->write_index = FFM_PACKET_SIZE;
yading@11: 
yading@11:     pts_start = get_dts(s, pos_min);
yading@11: 
yading@11:     pts = get_dts(s, pos_max);
yading@11: 
yading@11:     if (pts - 100000 <= pts_start) {
yading@11:         while (1) {
yading@11:             int64_t newpos;
yading@11:             int64_t newpts;
yading@11: 
yading@11:             newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
yading@11: 
yading@11:             if (newpos == pos_min)
yading@11:                 break;
yading@11: 
yading@11:             newpts = get_dts(s, newpos);
yading@11: 
yading@11:             if (newpts - 100000 <= pts) {
yading@11:                 pos_max = newpos;
yading@11:                 pts = newpts;
yading@11:             } else {
yading@11:                 pos_min = newpos;
yading@11:             }
yading@11:         }
yading@11:         ffm->write_index += pos_max;
yading@11:     }
yading@11: 
yading@11:  end:
yading@11:     avio_seek(pb, ptr, SEEK_SET);
yading@11: }
yading@11: 
yading@11: 
yading@11: static int ffm_close(AVFormatContext *s)
yading@11: {
yading@11:     int i;
yading@11: 
yading@11:     for (i = 0; i < s->nb_streams; i++)
yading@11:         av_freep(&s->streams[i]->codec->rc_eq);
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int ffm2_read_header(AVFormatContext *s)
yading@11: {
yading@11:     FFMContext *ffm = s->priv_data;
yading@11:     AVStream *st;
yading@11:     AVIOContext *pb = s->pb;
yading@11:     AVCodecContext *codec;
yading@11: 
yading@11:     ffm->packet_size = avio_rb32(pb);
yading@11:     if (ffm->packet_size != FFM_PACKET_SIZE)
yading@11:         goto fail;
yading@11:     ffm->write_index = avio_rb64(pb);
yading@11:     /* get also filesize */
yading@11:     if (pb->seekable) {
yading@11:         ffm->file_size = avio_size(pb);
yading@11:         if (ffm->write_index && 0)
yading@11:             adjust_write_index(s);
yading@11:     } else {
yading@11:         ffm->file_size = (UINT64_C(1) << 63) - 1;
yading@11:     }
yading@11: 
yading@11:     while(!url_feof(pb)) {
yading@11:         unsigned id = avio_rb32(pb);
yading@11:         unsigned size = avio_rb32(pb);
yading@11:         int64_t next = avio_tell(pb) + size;
yading@11:         char rc_eq_buf[128];
yading@11: 
yading@11:         if(!id)
yading@11:             break;
yading@11: 
yading@11:         switch(id) {
yading@11:         case MKBETAG('M', 'A', 'I', 'N'):
yading@11:             avio_rb32(pb); /* nb_streams */
yading@11:             avio_rb32(pb); /* total bitrate */
yading@11:             break;
yading@11:         case MKBETAG('C', 'O', 'M', 'M'):
yading@11:             st = avformat_new_stream(s, NULL);
yading@11:             if (!st)
yading@11:                 goto fail;
yading@11: 
yading@11:             avpriv_set_pts_info(st, 64, 1, 1000000);
yading@11: 
yading@11:             codec = st->codec;
yading@11:             /* generic info */
yading@11:             codec->codec_id = avio_rb32(pb);
yading@11:             codec->codec_type = avio_r8(pb);
yading@11:             codec->bit_rate = avio_rb32(pb);
yading@11:             codec->flags = avio_rb32(pb);
yading@11:             codec->flags2 = avio_rb32(pb);
yading@11:             codec->debug = avio_rb32(pb);
yading@11:             if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
yading@11:                 codec->extradata_size = avio_rb32(pb);
yading@11:                 codec->extradata = av_malloc(codec->extradata_size);
yading@11:                 if (!codec->extradata)
yading@11:                     return AVERROR(ENOMEM);
yading@11:                 avio_read(pb, codec->extradata, codec->extradata_size);
yading@11:             }
yading@11:             avio_seek(pb, next, SEEK_SET);
yading@11:             id = avio_rb32(pb);
yading@11:             size = avio_rb32(pb);
yading@11:             next = avio_tell(pb) + size;
yading@11:             switch(id) {
yading@11:             case MKBETAG('S', 'T', 'V', 'I'):
yading@11:                 codec->time_base.num = avio_rb32(pb);
yading@11:                 codec->time_base.den = avio_rb32(pb);
yading@11:                 codec->width = avio_rb16(pb);
yading@11:                 codec->height = avio_rb16(pb);
yading@11:                 codec->gop_size = avio_rb16(pb);
yading@11:                 codec->pix_fmt = avio_rb32(pb);
yading@11:                 codec->qmin = avio_r8(pb);
yading@11:                 codec->qmax = avio_r8(pb);
yading@11:                 codec->max_qdiff = avio_r8(pb);
yading@11:                 codec->qcompress = avio_rb16(pb) / 10000.0;
yading@11:                 codec->qblur = avio_rb16(pb) / 10000.0;
yading@11:                 codec->bit_rate_tolerance = avio_rb32(pb);
yading@11:                 avio_get_str(pb, INT_MAX, rc_eq_buf, sizeof(rc_eq_buf));
yading@11:                 codec->rc_eq = av_strdup(rc_eq_buf);
yading@11:                 codec->rc_max_rate = avio_rb32(pb);
yading@11:                 codec->rc_min_rate = avio_rb32(pb);
yading@11:                 codec->rc_buffer_size = avio_rb32(pb);
yading@11:                 codec->i_quant_factor = av_int2double(avio_rb64(pb));
yading@11:                 codec->b_quant_factor = av_int2double(avio_rb64(pb));
yading@11:                 codec->i_quant_offset = av_int2double(avio_rb64(pb));
yading@11:                 codec->b_quant_offset = av_int2double(avio_rb64(pb));
yading@11:                 codec->dct_algo = avio_rb32(pb);
yading@11:                 codec->strict_std_compliance = avio_rb32(pb);
yading@11:                 codec->max_b_frames = avio_rb32(pb);
yading@11:                 codec->mpeg_quant = avio_rb32(pb);
yading@11:                 codec->intra_dc_precision = avio_rb32(pb);
yading@11:                 codec->me_method = avio_rb32(pb);
yading@11:                 codec->mb_decision = avio_rb32(pb);
yading@11:                 codec->nsse_weight = avio_rb32(pb);
yading@11:                 codec->frame_skip_cmp = avio_rb32(pb);
yading@11:                 codec->rc_buffer_aggressivity = av_int2double(avio_rb64(pb));
yading@11:                 codec->codec_tag = avio_rb32(pb);
yading@11:                 codec->thread_count = avio_r8(pb);
yading@11:                 codec->coder_type = avio_rb32(pb);
yading@11:                 codec->me_cmp = avio_rb32(pb);
yading@11:                 codec->me_subpel_quality = avio_rb32(pb);
yading@11:                 codec->me_range = avio_rb32(pb);
yading@11:                 codec->keyint_min = avio_rb32(pb);
yading@11:                 codec->scenechange_threshold = avio_rb32(pb);
yading@11:                 codec->b_frame_strategy = avio_rb32(pb);
yading@11:                 codec->qcompress = av_int2double(avio_rb64(pb));
yading@11:                 codec->qblur = av_int2double(avio_rb64(pb));
yading@11:                 codec->max_qdiff = avio_rb32(pb);
yading@11:                 codec->refs = avio_rb32(pb);
yading@11:                 break;
yading@11:             case MKBETAG('S', 'T', 'A', 'U'):
yading@11:                 codec->sample_rate = avio_rb32(pb);
yading@11:                 codec->channels = avio_rl16(pb);
yading@11:                 codec->frame_size = avio_rl16(pb);
yading@11:                 break;
yading@11:             }
yading@11:             break;
yading@11:         }
yading@11:         avio_seek(pb, next, SEEK_SET);
yading@11:     }
yading@11: 
yading@11:     /* get until end of block reached */
yading@11:     while ((avio_tell(pb) % ffm->packet_size) != 0)
yading@11:         avio_r8(pb);
yading@11: 
yading@11:     /* init packet demux */
yading@11:     ffm->packet_ptr = ffm->packet;
yading@11:     ffm->packet_end = ffm->packet;
yading@11:     ffm->frame_offset = 0;
yading@11:     ffm->dts = 0;
yading@11:     ffm->read_state = READ_HEADER;
yading@11:     ffm->first_packet = 1;
yading@11:     return 0;
yading@11:  fail:
yading@11:     ffm_close(s);
yading@11:     return -1;
yading@11: }
yading@11: 
yading@11: static int ffm_read_header(AVFormatContext *s)
yading@11: {
yading@11:     FFMContext *ffm = s->priv_data;
yading@11:     AVStream *st;
yading@11:     AVIOContext *pb = s->pb;
yading@11:     AVCodecContext *codec;
yading@11:     int i, nb_streams;
yading@11:     uint32_t tag;
yading@11: 
yading@11:     /* header */
yading@11:     tag = avio_rl32(pb);
yading@11:     if (tag == MKTAG('F', 'F', 'M', '2'))
yading@11:         return ffm2_read_header(s);
yading@11:     if (tag != MKTAG('F', 'F', 'M', '1'))
yading@11:         goto fail;
yading@11:     ffm->packet_size = avio_rb32(pb);
yading@11:     if (ffm->packet_size != FFM_PACKET_SIZE)
yading@11:         goto fail;
yading@11:     ffm->write_index = avio_rb64(pb);
yading@11:     /* get also filesize */
yading@11:     if (pb->seekable) {
yading@11:         ffm->file_size = avio_size(pb);
yading@11:         if (ffm->write_index && 0)
yading@11:             adjust_write_index(s);
yading@11:     } else {
yading@11:         ffm->file_size = (UINT64_C(1) << 63) - 1;
yading@11:     }
yading@11: 
yading@11:     nb_streams = avio_rb32(pb);
yading@11:     avio_rb32(pb); /* total bitrate */
yading@11:     /* read each stream */
yading@11:     for(i=0;i<nb_streams;i++) {
yading@11:         char rc_eq_buf[128];
yading@11: 
yading@11:         st = avformat_new_stream(s, NULL);
yading@11:         if (!st)
yading@11:             goto fail;
yading@11: 
yading@11:         avpriv_set_pts_info(st, 64, 1, 1000000);
yading@11: 
yading@11:         codec = st->codec;
yading@11:         /* generic info */
yading@11:         codec->codec_id = avio_rb32(pb);
yading@11:         codec->codec_type = avio_r8(pb); /* codec_type */
yading@11:         codec->bit_rate = avio_rb32(pb);
yading@11:         codec->flags = avio_rb32(pb);
yading@11:         codec->flags2 = avio_rb32(pb);
yading@11:         codec->debug = avio_rb32(pb);
yading@11:         /* specific info */
yading@11:         switch(codec->codec_type) {
yading@11:         case AVMEDIA_TYPE_VIDEO:
yading@11:             codec->time_base.num = avio_rb32(pb);
yading@11:             codec->time_base.den = avio_rb32(pb);
yading@11:             codec->width = avio_rb16(pb);
yading@11:             codec->height = avio_rb16(pb);
yading@11:             codec->gop_size = avio_rb16(pb);
yading@11:             codec->pix_fmt = avio_rb32(pb);
yading@11:             codec->qmin = avio_r8(pb);
yading@11:             codec->qmax = avio_r8(pb);
yading@11:             codec->max_qdiff = avio_r8(pb);
yading@11:             codec->qcompress = avio_rb16(pb) / 10000.0;
yading@11:             codec->qblur = avio_rb16(pb) / 10000.0;
yading@11:             codec->bit_rate_tolerance = avio_rb32(pb);
yading@11:             avio_get_str(pb, INT_MAX, rc_eq_buf, sizeof(rc_eq_buf));
yading@11:             codec->rc_eq = av_strdup(rc_eq_buf);
yading@11:             codec->rc_max_rate = avio_rb32(pb);
yading@11:             codec->rc_min_rate = avio_rb32(pb);
yading@11:             codec->rc_buffer_size = avio_rb32(pb);
yading@11:             codec->i_quant_factor = av_int2double(avio_rb64(pb));
yading@11:             codec->b_quant_factor = av_int2double(avio_rb64(pb));
yading@11:             codec->i_quant_offset = av_int2double(avio_rb64(pb));
yading@11:             codec->b_quant_offset = av_int2double(avio_rb64(pb));
yading@11:             codec->dct_algo = avio_rb32(pb);
yading@11:             codec->strict_std_compliance = avio_rb32(pb);
yading@11:             codec->max_b_frames = avio_rb32(pb);
yading@11:             codec->mpeg_quant = avio_rb32(pb);
yading@11:             codec->intra_dc_precision = avio_rb32(pb);
yading@11:             codec->me_method = avio_rb32(pb);
yading@11:             codec->mb_decision = avio_rb32(pb);
yading@11:             codec->nsse_weight = avio_rb32(pb);
yading@11:             codec->frame_skip_cmp = avio_rb32(pb);
yading@11:             codec->rc_buffer_aggressivity = av_int2double(avio_rb64(pb));
yading@11:             codec->codec_tag = avio_rb32(pb);
yading@11:             codec->thread_count = avio_r8(pb);
yading@11:             codec->coder_type = avio_rb32(pb);
yading@11:             codec->me_cmp = avio_rb32(pb);
yading@11:             codec->me_subpel_quality = avio_rb32(pb);
yading@11:             codec->me_range = avio_rb32(pb);
yading@11:             codec->keyint_min = avio_rb32(pb);
yading@11:             codec->scenechange_threshold = avio_rb32(pb);
yading@11:             codec->b_frame_strategy = avio_rb32(pb);
yading@11:             codec->qcompress = av_int2double(avio_rb64(pb));
yading@11:             codec->qblur = av_int2double(avio_rb64(pb));
yading@11:             codec->max_qdiff = avio_rb32(pb);
yading@11:             codec->refs = avio_rb32(pb);
yading@11:             break;
yading@11:         case AVMEDIA_TYPE_AUDIO:
yading@11:             codec->sample_rate = avio_rb32(pb);
yading@11:             codec->channels = avio_rl16(pb);
yading@11:             codec->frame_size = avio_rl16(pb);
yading@11:             break;
yading@11:         default:
yading@11:             goto fail;
yading@11:         }
yading@11:         if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
yading@11:             codec->extradata_size = avio_rb32(pb);
yading@11:             codec->extradata = av_malloc(codec->extradata_size);
yading@11:             if (!codec->extradata)
yading@11:                 return AVERROR(ENOMEM);
yading@11:             avio_read(pb, codec->extradata, codec->extradata_size);
yading@11:         }
yading@11:     }
yading@11: 
yading@11:     /* get until end of block reached */
yading@11:     while ((avio_tell(pb) % ffm->packet_size) != 0)
yading@11:         avio_r8(pb);
yading@11: 
yading@11:     /* init packet demux */
yading@11:     ffm->packet_ptr = ffm->packet;
yading@11:     ffm->packet_end = ffm->packet;
yading@11:     ffm->frame_offset = 0;
yading@11:     ffm->dts = 0;
yading@11:     ffm->read_state = READ_HEADER;
yading@11:     ffm->first_packet = 1;
yading@11:     return 0;
yading@11:  fail:
yading@11:     ffm_close(s);
yading@11:     return -1;
yading@11: }
yading@11: 
yading@11: /* return < 0 if eof */
yading@11: static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
yading@11: {
yading@11:     int size;
yading@11:     FFMContext *ffm = s->priv_data;
yading@11:     int duration, ret;
yading@11: 
yading@11:     switch(ffm->read_state) {
yading@11:     case READ_HEADER:
yading@11:         if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0)
yading@11:             return ret;
yading@11: 
yading@11:         av_dlog(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
yading@11:                avio_tell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
yading@11:         if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
yading@11:             FRAME_HEADER_SIZE)
yading@11:             return -1;
yading@11:         if (ffm->header[1] & FLAG_DTS)
yading@11:             if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
yading@11:                 return -1;
yading@11:         ffm->read_state = READ_DATA;
yading@11:         /* fall thru */
yading@11:     case READ_DATA:
yading@11:         size = AV_RB24(ffm->header + 2);
yading@11:         if ((ret = ffm_is_avail_data(s, size)) < 0)
yading@11:             return ret;
yading@11: 
yading@11:         duration = AV_RB24(ffm->header + 5);
yading@11: 
yading@11:         if (av_new_packet(pkt, size) < 0) {
yading@11:             return AVERROR(ENOMEM);
yading@11:         }
yading@11:         pkt->stream_index = ffm->header[0];
yading@11:         if ((unsigned)pkt->stream_index >= s->nb_streams) {
yading@11:             av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
yading@11:             av_free_packet(pkt);
yading@11:             ffm->read_state = READ_HEADER;
yading@11:             return -1;
yading@11:         }
yading@11:         pkt->pos = avio_tell(s->pb);
yading@11:         if (ffm->header[1] & FLAG_KEY_FRAME)
yading@11:             pkt->flags |= AV_PKT_FLAG_KEY;
yading@11: 
yading@11:         ffm->read_state = READ_HEADER;
yading@11:         if (ffm_read_data(s, pkt->data, size, 0) != size) {
yading@11:             /* bad case: desynchronized packet. we cancel all the packet loading */
yading@11:             av_free_packet(pkt);
yading@11:             return -1;
yading@11:         }
yading@11:         pkt->pts = AV_RB64(ffm->header+8);
yading@11:         if (ffm->header[1] & FLAG_DTS)
yading@11:             pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
yading@11:         else
yading@11:             pkt->dts = pkt->pts;
yading@11:         pkt->duration = duration;
yading@11:         break;
yading@11:     }
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: /* seek to a given time in the file. The file read pointer is
yading@11:    positioned at or before pts. XXX: the following code is quite
yading@11:    approximative */
yading@11: static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
yading@11: {
yading@11:     FFMContext *ffm = s->priv_data;
yading@11:     int64_t pos_min, pos_max, pos;
yading@11:     int64_t pts_min, pts_max, pts;
yading@11:     double pos1;
yading@11: 
yading@11:     av_dlog(s, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
yading@11:     /* find the position using linear interpolation (better than
yading@11:        dichotomy in typical cases) */
yading@11:     if (ffm->write_index && ffm->write_index < ffm->file_size) {
yading@11:         if (get_dts(s, FFM_PACKET_SIZE) < wanted_pts) {
yading@11:             pos_min = FFM_PACKET_SIZE;
yading@11:             pos_max = ffm->write_index - FFM_PACKET_SIZE;
yading@11:         } else {
yading@11:             pos_min = ffm->write_index;
yading@11:             pos_max = ffm->file_size - FFM_PACKET_SIZE;
yading@11:         }
yading@11:     } else {
yading@11:         pos_min = FFM_PACKET_SIZE;
yading@11:         pos_max = ffm->file_size - FFM_PACKET_SIZE;
yading@11:     }
yading@11:     while (pos_min <= pos_max) {
yading@11:         pts_min = get_dts(s, pos_min);
yading@11:         pts_max = get_dts(s, pos_max);
yading@11:         if (pts_min > wanted_pts || pts_max <= wanted_pts) {
yading@11:             pos = pts_min > wanted_pts ? pos_min : pos_max;
yading@11:             goto found;
yading@11:         }
yading@11:         /* linear interpolation */
yading@11:         pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
yading@11:             (double)(pts_max - pts_min);
yading@11:         pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
yading@11:         if (pos <= pos_min)
yading@11:             pos = pos_min;
yading@11:         else if (pos >= pos_max)
yading@11:             pos = pos_max;
yading@11:         pts = get_dts(s, pos);
yading@11:         /* check if we are lucky */
yading@11:         if (pts == wanted_pts) {
yading@11:             goto found;
yading@11:         } else if (pts > wanted_pts) {
yading@11:             pos_max = pos - FFM_PACKET_SIZE;
yading@11:         } else {
yading@11:             pos_min = pos + FFM_PACKET_SIZE;
yading@11:         }
yading@11:     }
yading@11:     pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
yading@11: 
yading@11:  found:
yading@11:     if (ffm_seek1(s, pos) < 0)
yading@11:         return -1;
yading@11: 
yading@11:     /* reset read state */
yading@11:     ffm->read_state = READ_HEADER;
yading@11:     ffm->packet_ptr = ffm->packet;
yading@11:     ffm->packet_end = ffm->packet;
yading@11:     ffm->first_packet = 1;
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int ffm_probe(AVProbeData *p)
yading@11: {
yading@11:     if (
yading@11:         p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
yading@11:         (p->buf[3] == '1' || p->buf[3] == '2'))
yading@11:         return AVPROBE_SCORE_MAX + 1;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: AVInputFormat ff_ffm_demuxer = {
yading@11:     .name           = "ffm",
yading@11:     .long_name      = NULL_IF_CONFIG_SMALL("FFM (FFserver live feed)"),
yading@11:     .priv_data_size = sizeof(FFMContext),
yading@11:     .read_probe     = ffm_probe,
yading@11:     .read_header    = ffm_read_header,
yading@11:     .read_packet    = ffm_read_packet,
yading@11:     .read_close     = ffm_close,
yading@11:     .read_seek      = ffm_seek,
yading@11: };