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* FFM (ffserver live feed) demuxer
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* Copyright (c) 2001 Fabrice Bellard.
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* This file is part of FFmpeg.
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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#ifdef CONFIG_FFSERVER
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int64_t ffm_read_write_index(int fd)
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lseek(fd, 8, SEEK_SET);
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void ffm_write_write_index(int fd, int64_t pos)
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buf[i] = (pos >> (56 - i * 8)) & 0xff;
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lseek(fd, 8, SEEK_SET);
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void ffm_set_write_index(AVFormatContext *s, int64_t pos, int64_t file_size)
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FFMContext *ffm = s->priv_data;
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ffm->write_index = pos;
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ffm->file_size = file_size;
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#endif // CONFIG_FFSERVER
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static int ffm_is_avail_data(AVFormatContext *s, int size)
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FFMContext *ffm = s->priv_data;
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int64_t pos, avail_size;
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len = ffm->packet_end - ffm->packet_ptr;
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pos = url_ftell(s->pb);
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if (pos == ffm->write_index) {
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/* exactly at the end of stream */
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} else if (pos < ffm->write_index) {
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avail_size = ffm->write_index - pos;
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avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);
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avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;
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if (size <= avail_size)
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/* first is true if we read the frame header */
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static int ffm_read_data(AVFormatContext *s,
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uint8_t *buf, int size, int header)
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FFMContext *ffm = s->priv_data;
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ByteIOContext *pb = s->pb;
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int len, fill_size, size1, frame_offset;
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len = ffm->packet_end - ffm->packet_ptr;
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if (url_ftell(pb) == ffm->file_size)
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url_fseek(pb, ffm->packet_size, SEEK_SET);
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get_be16(pb); /* PACKET_ID */
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fill_size = get_be16(pb);
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ffm->dts = get_be64(pb);
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frame_offset = get_be16(pb);
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get_buffer(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);
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ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);
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if (ffm->packet_end < ffm->packet || frame_offset < 0)
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/* if first packet or resynchronization packet, we must
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handle it specifically */
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if (ffm->first_packet || (frame_offset & 0x8000)) {
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/* This packet has no frame headers in it */
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if (url_ftell(pb) >= ffm->packet_size * 3) {
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url_fseek(pb, -ffm->packet_size * 2, SEEK_CUR);
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/* This is bad, we cannot find a valid frame header */
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ffm->first_packet = 0;
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if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE)
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ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;
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ffm->packet_ptr = ffm->packet;
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memcpy(buf, ffm->packet_ptr, len);
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ffm->packet_ptr += len;
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/* pos is between 0 and file_size - FFM_PACKET_SIZE. It is translated
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by the write position inside this function */
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static void ffm_seek1(AVFormatContext *s, int64_t pos1)
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FFMContext *ffm = s->priv_data;
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ByteIOContext *pb = s->pb;
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pos = pos1 + ffm->write_index;
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if (pos >= ffm->file_size)
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pos -= (ffm->file_size - FFM_PACKET_SIZE);
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av_log(s, AV_LOG_DEBUG, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);
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url_fseek(pb, pos, SEEK_SET);
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static int64_t get_dts(AVFormatContext *s, int64_t pos)
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ByteIOContext *pb = s->pb;
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av_log(s, AV_LOG_DEBUG, "pts=%0.6f\n", pts / 1000000.0);
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static void adjust_write_index(AVFormatContext *s)
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FFMContext *ffm = s->priv_data;
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ByteIOContext *pb = s->pb;
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//int64_t orig_write_index = ffm->write_index;
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int64_t pos_min, pos_max;
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int64_t ptr = url_ftell(pb);
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pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
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pts_start = get_dts(s, pos_min);
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pts = get_dts(s, pos_max);
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if (pts - 100000 > pts_start)
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ffm->write_index = FFM_PACKET_SIZE;
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pts_start = get_dts(s, pos_min);
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pts = get_dts(s, pos_max);
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if (pts - 100000 <= pts_start) {
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newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;
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if (newpos == pos_min)
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newpts = get_dts(s, newpos);
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if (newpts - 100000 <= pts) {
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ffm->write_index += pos_max;
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//printf("Adjusted write index from %"PRId64" to %"PRId64": pts=%0.6f\n", orig_write_index, ffm->write_index, pts / 1000000.);
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//printf("pts range %0.6f - %0.6f\n", get_dts(s, 0) / 1000000. , get_dts(s, ffm->file_size - 2 * FFM_PACKET_SIZE) / 1000000. );
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url_fseek(pb, ptr, SEEK_SET);
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static int ffm_read_header(AVFormatContext *s, AVFormatParameters *ap)
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FFMContext *ffm = s->priv_data;
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ByteIOContext *pb = s->pb;
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AVCodecContext *codec;
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if (tag != MKTAG('F', 'F', 'M', '1'))
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ffm->packet_size = get_be32(pb);
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if (ffm->packet_size != FFM_PACKET_SIZE)
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ffm->write_index = get_be64(pb);
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/* get also filesize */
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if (!url_is_streamed(pb)) {
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ffm->file_size = url_fsize(pb);
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adjust_write_index(s);
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ffm->file_size = (UINT64_C(1) << 63) - 1;
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nb_streams = get_be32(pb);
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get_be32(pb); /* total bitrate */
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/* read each stream */
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for(i=0;i<nb_streams;i++) {
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st = av_new_stream(s, 0);
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av_set_pts_info(st, 64, 1, 1000000);
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codec->codec_id = get_be32(pb);
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codec->codec_type = get_byte(pb); /* codec_type */
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codec->bit_rate = get_be32(pb);
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st->quality = get_be32(pb);
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codec->flags = get_be32(pb);
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codec->flags2 = get_be32(pb);
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codec->debug = get_be32(pb);
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switch(codec->codec_type) {
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case CODEC_TYPE_VIDEO:
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codec->time_base.num = get_be32(pb);
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codec->time_base.den = get_be32(pb);
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codec->width = get_be16(pb);
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codec->height = get_be16(pb);
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codec->gop_size = get_be16(pb);
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codec->pix_fmt = get_be32(pb);
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codec->qmin = get_byte(pb);
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codec->qmax = get_byte(pb);
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codec->max_qdiff = get_byte(pb);
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codec->qcompress = get_be16(pb) / 10000.0;
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codec->qblur = get_be16(pb) / 10000.0;
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codec->bit_rate_tolerance = get_be32(pb);
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codec->rc_eq = av_strdup(get_strz(pb, rc_eq_buf, sizeof(rc_eq_buf)));
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codec->rc_max_rate = get_be32(pb);
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codec->rc_min_rate = get_be32(pb);
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codec->rc_buffer_size = get_be32(pb);
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codec->i_quant_factor = av_int2dbl(get_be64(pb));
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codec->b_quant_factor = av_int2dbl(get_be64(pb));
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codec->i_quant_offset = av_int2dbl(get_be64(pb));
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codec->b_quant_offset = av_int2dbl(get_be64(pb));
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codec->dct_algo = get_be32(pb);
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codec->strict_std_compliance = get_be32(pb);
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codec->max_b_frames = get_be32(pb);
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codec->luma_elim_threshold = get_be32(pb);
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codec->chroma_elim_threshold = get_be32(pb);
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codec->mpeg_quant = get_be32(pb);
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codec->intra_dc_precision = get_be32(pb);
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codec->me_method = get_be32(pb);
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codec->mb_decision = get_be32(pb);
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codec->nsse_weight = get_be32(pb);
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codec->frame_skip_cmp = get_be32(pb);
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codec->rc_buffer_aggressivity = av_int2dbl(get_be64(pb));
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codec->codec_tag = get_be32(pb);
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codec->thread_count = get_byte(pb);
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case CODEC_TYPE_AUDIO:
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codec->sample_rate = get_be32(pb);
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codec->channels = get_le16(pb);
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codec->frame_size = get_le16(pb);
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if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
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codec->extradata_size = get_be32(pb);
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codec->extradata = av_malloc(codec->extradata_size);
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if (!codec->extradata)
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return AVERROR(ENOMEM);
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get_buffer(pb, codec->extradata, codec->extradata_size);
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/* get until end of block reached */
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while ((url_ftell(pb) % ffm->packet_size) != 0)
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/* init packet demux */
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ffm->packet_ptr = ffm->packet;
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ffm->packet_end = ffm->packet;
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ffm->frame_offset = 0;
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ffm->read_state = READ_HEADER;
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ffm->first_packet = 1;
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for(i=0;i<s->nb_streams;i++) {
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/* return < 0 if eof */
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static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)
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FFMContext *ffm = s->priv_data;
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switch(ffm->read_state) {
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if (!ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) {
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return AVERROR(EAGAIN);
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dprintf(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",
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url_ftell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);
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if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=
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return AVERROR(EAGAIN);
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if (ffm->header[1] & FLAG_DTS)
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if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)
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return AVERROR(EAGAIN);
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av_hexdump_log(s, AV_LOG_DEBUG, ffm->header, FRAME_HEADER_SIZE);
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ffm->read_state = READ_DATA;
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size = AV_RB24(ffm->header + 2);
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if (!ffm_is_avail_data(s, size)) {
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return AVERROR(EAGAIN);
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duration = AV_RB24(ffm->header + 5);
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av_new_packet(pkt, size);
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pkt->stream_index = ffm->header[0];
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if ((unsigned)pkt->stream_index >= s->nb_streams) {
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av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);
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ffm->read_state = READ_HEADER;
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return AVERROR(EAGAIN);
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pkt->pos = url_ftell(s->pb);
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if (ffm->header[1] & FLAG_KEY_FRAME)
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pkt->flags |= PKT_FLAG_KEY;
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ffm->read_state = READ_HEADER;
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if (ffm_read_data(s, pkt->data, size, 0) != size) {
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/* bad case: desynchronized packet. we cancel all the packet loading */
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return AVERROR(EAGAIN);
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pkt->pts = AV_RB64(ffm->header+8);
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if (ffm->header[1] & FLAG_DTS)
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pkt->dts = pkt->pts - AV_RB32(ffm->header+16);
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pkt->duration = duration;
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/* seek to a given time in the file. The file read pointer is
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positioned at or before pts. XXX: the following code is quite
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static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)
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FFMContext *ffm = s->priv_data;
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int64_t pos_min, pos_max, pos;
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int64_t pts_min, pts_max, pts;
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av_log(s, AV_LOG_DEBUG, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);
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/* find the position using linear interpolation (better than
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dichotomy in typical cases) */
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pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;
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while (pos_min <= pos_max) {
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pts_min = get_dts(s, pos_min);
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pts_max = get_dts(s, pos_max);
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/* linear interpolation */
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pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /
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(double)(pts_max - pts_min);
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pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;
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else if (pos >= pos_max)
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pts = get_dts(s, pos);
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/* check if we are lucky */
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if (pts == wanted_pts) {
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} else if (pts > wanted_pts) {
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pos_max = pos - FFM_PACKET_SIZE;
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pos_min = pos + FFM_PACKET_SIZE;
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pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
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pos -= FFM_PACKET_SIZE;
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/* reset read state */
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ffm->read_state = READ_HEADER;
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ffm->packet_ptr = ffm->packet;
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ffm->packet_end = ffm->packet;
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ffm->first_packet = 1;
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static int ffm_probe(AVProbeData *p)
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p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&
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return AVPROBE_SCORE_MAX + 1;
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AVInputFormat ffm_demuxer = {
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NULL_IF_CONFIG_SMALL("FFM (FFserver live feed) format"),