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2bd83ef26a
Pro-MPEG Code of Practice #3 release 2 forward error correction for rtp_mpegts streams Signed-off-by: Vlad Tarca <vtarca@mobibase.com> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
482 lines
14 KiB
C
482 lines
14 KiB
C
/*
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* Pro-MPEG Code of Practice #3 Release 2 FEC
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* Copyright (c) 2016 Mobibase, France (http://www.mobibase.com)
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*
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* This file is part of FFmpeg.
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*
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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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*
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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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*
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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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*/
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/**
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* @file
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* Pro-MPEG Code of Practice #3 Release 2 FEC protocol
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* @author Vlad Tarca <vlad.tarca@gmail.com>
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*/
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/*
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* Reminder:
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[RFC 2733] FEC Packet Structure
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| RTP Header |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| FEC Header |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| FEC Payload |
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| |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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[RFC 3550] RTP header
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0 1 2 3
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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|V=2|P|X| CC |M| PT | sequence number |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| timestamp |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| synchronization source (SSRC) identifier |
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+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
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| contributing source (CSRC) identifiers |
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| .... |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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[RFC 3550] RTP header extension (after CSRC)
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0 1 2 3
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0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| defined by profile | length |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| header extension |
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| .... |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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[Pro-MPEG COP3] FEC Header
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| SNBase low bits | length recovery |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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|E| PT recovery | mask |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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| TS recovery |
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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|X|D|type |index| offset | NA |SNBase ext bits|
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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*/
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#include "libavutil/avstring.h"
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#include "libavutil/intreadwrite.h"
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#include "libavutil/opt.h"
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#include "libavutil/parseutils.h"
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#include "libavutil/random_seed.h"
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#include "avformat.h"
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#include "config.h"
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#include "url.h"
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#define PROMPEG_RTP_PT 0x60
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#define PROMPEG_FEC_COL 0x0
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#define PROMPEG_FEC_ROW 0x1
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typedef struct PrompegFec {
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uint16_t sn;
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uint32_t ts;
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uint8_t *bitstring;
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} PrompegFec;
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typedef struct PrompegContext {
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const AVClass *class;
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URLContext *fec_col_hd, *fec_row_hd;
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PrompegFec **fec_arr, **fec_col_tmp, **fec_col, *fec_row;
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int ttl;
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uint8_t l, d;
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uint8_t *rtp_buf;
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uint16_t rtp_col_sn, rtp_row_sn;
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uint16_t length_recovery;
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int packet_size;
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int packet_idx, packet_idx_max;
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int fec_arr_len;
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int bitstring_size;
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int rtp_buf_size;
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int init;
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int first;
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} PrompegContext;
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#define OFFSET(x) offsetof(PrompegContext, x)
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#define E AV_OPT_FLAG_ENCODING_PARAM
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static const AVOption options[] = {
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{ "ttl", "Time to live (in milliseconds, multicast only)", OFFSET(ttl), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = E },
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{ "l", "FEC L", OFFSET(l), AV_OPT_TYPE_INT, { .i64 = 5 }, 4, 20, .flags = E },
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{ "d", "FEC D", OFFSET(d), AV_OPT_TYPE_INT, { .i64 = 5 }, 4, 20, .flags = E },
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{ NULL }
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};
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static const AVClass prompeg_class = {
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.class_name = "prompeg",
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.item_name = av_default_item_name,
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.option = options,
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.version = LIBAVUTIL_VERSION_INT,
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};
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static void xor_fast(const uint8_t *in1, const uint8_t *in2, uint8_t *out, int size) {
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int i, n, s;
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#if HAVE_FAST_64BIT
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uint64_t v1, v2;
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n = size / sizeof (uint64_t);
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s = n * sizeof (uint64_t);
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for (i = 0; i < n; i++) {
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v1 = AV_RN64A(in1);
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v2 = AV_RN64A(in2);
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AV_WN64A(out, v1 ^ v2);
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in1 += 8;
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in2 += 8;
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out += 8;
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}
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#else
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uint32_t v1, v2;
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n = size / sizeof (uint32_t);
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s = n * sizeof (uint32_t);
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for (i = 0; i < n; i++) {
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v1 = AV_RN32A(in1);
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v2 = AV_RN32A(in2);
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AV_WN32A(out, v1 ^ v2);
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in1 += 4;
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in2 += 4;
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out += 4;
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}
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#endif
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n = size - s;
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for (i = 0; i < n; i++) {
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out[i] = in1[i] ^ in2[i];
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}
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}
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static int prompeg_create_bitstring(URLContext *h, const uint8_t *buf, int size,
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uint8_t **bitstring) {
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PrompegContext *s = h->priv_data;
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uint8_t *b;
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if (size < 12 || (buf[0] & 0xc0) != 0x80 || (buf[1] & 0x7f) != 0x21) {
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av_log(h, AV_LOG_ERROR, "Unsupported stream format (expected MPEG-TS over RTP)\n");
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return AVERROR(EINVAL);
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}
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if (size != s->packet_size) {
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av_log(h, AV_LOG_ERROR, "The RTP packet size must be constant (set pkt_size)\n");
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return AVERROR(EINVAL);
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}
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*bitstring = av_malloc(s->bitstring_size);
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if (!*bitstring) {
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av_log(h, AV_LOG_ERROR, "Failed to allocate the bitstring buffer\n");
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return AVERROR(ENOMEM);
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}
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b = *bitstring;
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// P, X, CC
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b[0] = buf[0] & 0x3f;
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// M, PT
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b[1] = buf[1];
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// Timestamp
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b[2] = buf[4];
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b[3] = buf[5];
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b[4] = buf[6];
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b[5] = buf[7];
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/*
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* length_recovery: the unsigned network-ordered sum of lengths of CSRC,
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* padding, extension and media payload
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*/
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AV_WB16(b + 6, s->length_recovery);
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// Payload
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memcpy(b + 8, buf + 12, s->length_recovery);
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return 0;
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}
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static int prompeg_write_fec(URLContext *h, PrompegFec *fec, uint8_t type) {
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PrompegContext *s = h->priv_data;
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URLContext *hd;
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uint8_t *buf = s->rtp_buf; // zero-filled
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uint8_t *b = fec->bitstring;
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uint16_t sn;
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int ret;
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sn = type == PROMPEG_FEC_COL ? ++s->rtp_col_sn : ++s->rtp_row_sn;
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// V, P, X, CC
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buf[0] = 0x80 | (b[0] & 0x3f);
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// M, PT
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buf[1] = (b[1] & 0x80) | PROMPEG_RTP_PT;
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// SN
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AV_WB16(buf + 2, sn);
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// TS
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AV_WB32(buf + 4, fec->ts);
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// CSRC=0
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//AV_WB32(buf + 8, 0);
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// SNBase low bits
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AV_WB16(buf + 12, fec->sn);
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// Length recovery
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buf[14] = b[6];
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buf[15] = b[7];
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// E=1, PT recovery
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buf[16] = 0x80 | b[1];
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// Mask=0
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//buf[17] = 0x0;
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//buf[18] = 0x0;
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//buf[19] = 0x0;
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// TS recovery
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buf[20] = b[2];
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buf[21] = b[3];
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buf[22] = b[4];
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buf[23] = b[5];
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// X=0, D, type=0, index=0
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buf[24] = type == PROMPEG_FEC_COL ? 0x0 : 0x40;
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// offset
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buf[25] = type == PROMPEG_FEC_COL ? s->l : 0x1;
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// NA
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buf[26] = type == PROMPEG_FEC_COL ? s->d : s->l;
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// SNBase ext bits=0
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//buf[27] = 0x0;
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// Payload
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memcpy(buf + 28, b + 8, s->length_recovery);
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hd = type == PROMPEG_FEC_COL ? s->fec_col_hd : s->fec_row_hd;
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ret = ffurl_write(hd, buf, s->rtp_buf_size);
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return ret;
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}
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static int prompeg_open(URLContext *h, const char *uri, int flags) {
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PrompegContext *s = h->priv_data;
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AVDictionary *udp_opts = NULL;
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int rtp_port;
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char hostname[256];
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char buf[1024];
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s->fec_col_hd = NULL;
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s->fec_row_hd = NULL;
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if (s->l * s->d > 100) {
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av_log(h, AV_LOG_ERROR, "L * D must be <= 100\n");
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return AVERROR(EINVAL);
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}
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av_url_split(NULL, 0, NULL, 0, hostname, sizeof (hostname), &rtp_port,
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NULL, 0, uri);
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if (rtp_port < 1 || rtp_port > UINT16_MAX - 4) {
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av_log(h, AV_LOG_ERROR, "Invalid RTP base port %d\n", rtp_port);
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return AVERROR(EINVAL);
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}
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if (s->ttl > 0) {
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snprintf(buf, sizeof (buf), "%d", s->ttl);
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av_dict_set(&udp_opts, "ttl", buf, 0);
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}
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ff_url_join(buf, sizeof (buf), "udp", NULL, hostname, rtp_port + 2, NULL);
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if (ffurl_open_whitelist(&s->fec_col_hd, buf, flags, &h->interrupt_callback,
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&udp_opts, h->protocol_whitelist, h->protocol_blacklist, h) < 0)
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goto fail;
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ff_url_join(buf, sizeof (buf), "udp", NULL, hostname, rtp_port + 4, NULL);
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if (ffurl_open_whitelist(&s->fec_row_hd, buf, flags, &h->interrupt_callback,
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&udp_opts, h->protocol_whitelist, h->protocol_blacklist, h) < 0)
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goto fail;
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h->max_packet_size = s->fec_col_hd->max_packet_size;
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s->init = 1;
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av_dict_free(&udp_opts);
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av_log(h, AV_LOG_INFO, "ProMPEG CoP#3-R2 FEC L=%d D=%d\n", s->l, s->d);
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return 0;
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fail:
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ffurl_closep(&s->fec_col_hd);
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ffurl_closep(&s->fec_row_hd);
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av_dict_free(&udp_opts);
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return AVERROR(EIO);
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}
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static int prompeg_init(URLContext *h, const uint8_t *buf, int size) {
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PrompegContext *s = h->priv_data;
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uint32_t seed;
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int i;
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s->fec_arr = NULL;
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s->rtp_buf = NULL;
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if (size < 12 || size > UINT16_MAX + 12) {
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av_log(h, AV_LOG_ERROR, "Invalid RTP packet size\n");
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return AVERROR_INVALIDDATA;
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}
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s->packet_idx = 0;
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s->packet_idx_max = s->l * s->d;
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s->packet_size = size;
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s->length_recovery = size - 12;
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s->rtp_buf_size = 28 + s->length_recovery; // 12 + 16: RTP + FEC headers
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s->bitstring_size = 8 + s->length_recovery; // 8: P, X, CC, M, PT, SN, TS
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s->fec_arr_len = 1 + 2 * s->l; // row + column tmp + column out
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if (h->flags & AVFMT_FLAG_BITEXACT) {
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s->rtp_col_sn = 0;
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s->rtp_row_sn = 0;
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} else {
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seed = av_get_random_seed();
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s->rtp_col_sn = seed & 0x0fff;
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s->rtp_row_sn = (seed >> 16) & 0x0fff;
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}
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s->fec_arr = av_malloc_array(s->fec_arr_len, sizeof (PrompegFec*));
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if (!s->fec_arr) {
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goto fail;
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}
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for (i = 0; i < s->fec_arr_len; i++) {
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s->fec_arr[i] = av_malloc(sizeof (PrompegFec));
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if (!s->fec_arr[i]) {
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goto fail;
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}
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s->fec_arr[i]->bitstring = av_malloc_array(s->bitstring_size, sizeof (uint8_t));
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if (!s->fec_arr[i]->bitstring) {
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av_freep(&s->fec_arr[i]);
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goto fail;
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}
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}
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s->fec_row = *s->fec_arr;
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s->fec_col = s->fec_arr + 1;
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s->fec_col_tmp = s->fec_arr + 1 + s->l;
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s->rtp_buf = av_malloc_array(s->rtp_buf_size, sizeof (uint8_t));
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if (!s->rtp_buf) {
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goto fail;
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}
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memset(s->rtp_buf, 0, s->rtp_buf_size);
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s->init = 0;
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s->first = 1;
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return 0;
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fail:
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av_log(h, AV_LOG_ERROR, "Failed to allocate the FEC buffer\n");
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return AVERROR(ENOMEM);
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}
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static int prompeg_write(URLContext *h, const uint8_t *buf, int size) {
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PrompegContext *s = h->priv_data;
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PrompegFec *fec_tmp;
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uint8_t *bitstring = NULL;
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int col_idx, col_out_idx, row_idx;
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int ret, written = 0;
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if (s->init && ((ret = prompeg_init(h, buf, size)) < 0))
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goto end;
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if ((ret = prompeg_create_bitstring(h, buf, size, &bitstring)) < 0)
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goto end;
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col_idx = s->packet_idx % s->l;
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row_idx = s->packet_idx / s->l % s->d;
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// FEC' (row) send block-aligned, xor
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if (col_idx == 0) {
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if (!s->first || s->packet_idx > 0) {
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if ((ret = prompeg_write_fec(h, s->fec_row, PROMPEG_FEC_ROW)) < 0)
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goto end;
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written += ret;
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}
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memcpy(s->fec_row->bitstring, bitstring, s->bitstring_size);
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s->fec_row->sn = AV_RB16(buf + 2);
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s->fec_row->ts = AV_RB32(buf + 4);
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} else {
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xor_fast(s->fec_row->bitstring, bitstring, s->fec_row->bitstring,
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s->bitstring_size);
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}
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// FEC (column) xor
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if (row_idx == 0) {
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if (!s->first) {
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// swap fec_col and fec_col_tmp
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fec_tmp = s->fec_col[col_idx];
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s->fec_col[col_idx] = s->fec_col_tmp[col_idx];
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s->fec_col_tmp[col_idx] = fec_tmp;
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}
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memcpy(s->fec_col_tmp[col_idx]->bitstring, bitstring, s->bitstring_size);
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s->fec_col_tmp[col_idx]->sn = AV_RB16(buf + 2);
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s->fec_col_tmp[col_idx]->ts = AV_RB32(buf + 4);
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} else {
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xor_fast(s->fec_col_tmp[col_idx]->bitstring, bitstring,
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s->fec_col_tmp[col_idx]->bitstring, s->bitstring_size);
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}
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// FEC (column) send block-aligned
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if (!s->first && s->packet_idx % s->d == 0) {
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col_out_idx = s->packet_idx / s->l;
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if ((ret = prompeg_write_fec(h, s->fec_col[col_out_idx], PROMPEG_FEC_COL)) < 0)
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goto end;
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written += ret;
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}
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if (++s->packet_idx >= s->packet_idx_max) {
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s->packet_idx = 0;
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if (s->first)
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s->first = 0;
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}
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ret = written;
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end:
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av_free(bitstring);
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return ret;
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}
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static int prompeg_close(URLContext *h) {
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PrompegContext *s = h->priv_data;
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int i;
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ffurl_closep(&s->fec_col_hd);
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ffurl_closep(&s->fec_row_hd);
|
|
|
|
if (s->fec_arr) {
|
|
for (i = 0; i < s->fec_arr_len; i++) {
|
|
av_free(s->fec_arr[i]->bitstring);
|
|
av_freep(&s->fec_arr[i]);
|
|
}
|
|
av_freep(&s->fec_arr);
|
|
}
|
|
av_freep(&s->rtp_buf);
|
|
|
|
return 0;
|
|
}
|
|
|
|
const URLProtocol ff_prompeg_protocol = {
|
|
.name = "prompeg",
|
|
.url_open = prompeg_open,
|
|
.url_write = prompeg_write,
|
|
.url_close = prompeg_close,
|
|
.priv_data_size = sizeof(PrompegContext),
|
|
.flags = URL_PROTOCOL_FLAG_NETWORK,
|
|
.priv_data_class = &prompeg_class,
|
|
};
|