| /* |
| * Pro-MPEG Code of Practice #3 Release 2 FEC |
| * Copyright (c) 2016 Mobibase, France (http://www.mobibase.com) |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| /** |
| * @file |
| * Pro-MPEG Code of Practice #3 Release 2 FEC protocol |
| * @author Vlad Tarca <vlad.tarca@gmail.com> |
| */ |
| |
| /* |
| * Reminder: |
| |
| [RFC 2733] FEC Packet Structure |
| |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| | RTP Header | |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| | FEC Header | |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| | FEC Payload | |
| | | |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |
| |
| [RFC 3550] RTP header |
| |
| 0 1 2 3 |
| 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 |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |V=2|P|X| CC |M| PT | sequence number | |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| | timestamp | |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| | synchronization source (SSRC) identifier | |
| +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ |
| | contributing source (CSRC) identifiers | |
| | .... | |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |
| [RFC 3550] RTP header extension (after CSRC) |
| |
| 0 1 2 3 |
| 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 |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| | defined by profile | length | |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| | header extension | |
| | .... | |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |
| [Pro-MPEG COP3] FEC Header |
| |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| | SNBase low bits | length recovery | |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |E| PT recovery | mask | |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| | TS recovery | |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |X|D|type |index| offset | NA |SNBase ext bits| |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |
| */ |
| |
| #include "libavutil/avstring.h" |
| #include "libavutil/intreadwrite.h" |
| #include "libavutil/opt.h" |
| #include "libavutil/parseutils.h" |
| #include "libavutil/random_seed.h" |
| #include "avformat.h" |
| #include "config.h" |
| #include "url.h" |
| |
| #define PROMPEG_RTP_PT 0x60 |
| #define PROMPEG_FEC_COL 0x0 |
| #define PROMPEG_FEC_ROW 0x1 |
| |
| typedef struct PrompegFec { |
| uint16_t sn; |
| uint32_t ts; |
| uint8_t *bitstring; |
| } PrompegFec; |
| |
| typedef struct PrompegContext { |
| const AVClass *class; |
| URLContext *fec_col_hd, *fec_row_hd; |
| PrompegFec **fec_arr, **fec_col_tmp, **fec_col, *fec_row; |
| int ttl; |
| uint8_t l, d; |
| uint8_t *rtp_buf; |
| uint16_t rtp_col_sn, rtp_row_sn; |
| uint16_t length_recovery; |
| int packet_size; |
| int packet_idx, packet_idx_max; |
| int fec_arr_len; |
| int bitstring_size; |
| int rtp_buf_size; |
| int init; |
| int first; |
| } PrompegContext; |
| |
| #define OFFSET(x) offsetof(PrompegContext, x) |
| #define E AV_OPT_FLAG_ENCODING_PARAM |
| |
| static const AVOption options[] = { |
| { "ttl", "Time to live (in milliseconds, multicast only)", OFFSET(ttl), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = E }, |
| { "l", "FEC L", OFFSET(l), AV_OPT_TYPE_INT, { .i64 = 5 }, 4, 20, .flags = E }, |
| { "d", "FEC D", OFFSET(d), AV_OPT_TYPE_INT, { .i64 = 5 }, 4, 20, .flags = E }, |
| { NULL } |
| }; |
| |
| static const AVClass prompeg_class = { |
| .class_name = "prompeg", |
| .item_name = av_default_item_name, |
| .option = options, |
| .version = LIBAVUTIL_VERSION_INT, |
| }; |
| |
| static void xor_fast(const uint8_t *in1, const uint8_t *in2, uint8_t *out, int size) { |
| int i, n, s; |
| |
| #if HAVE_FAST_64BIT |
| uint64_t v1, v2; |
| |
| n = size / sizeof (uint64_t); |
| s = n * sizeof (uint64_t); |
| |
| for (i = 0; i < n; i++) { |
| v1 = AV_RN64A(in1); |
| v2 = AV_RN64A(in2); |
| AV_WN64A(out, v1 ^ v2); |
| in1 += 8; |
| in2 += 8; |
| out += 8; |
| } |
| #else |
| uint32_t v1, v2; |
| |
| n = size / sizeof (uint32_t); |
| s = n * sizeof (uint32_t); |
| |
| for (i = 0; i < n; i++) { |
| v1 = AV_RN32A(in1); |
| v2 = AV_RN32A(in2); |
| AV_WN32A(out, v1 ^ v2); |
| in1 += 4; |
| in2 += 4; |
| out += 4; |
| } |
| #endif |
| |
| n = size - s; |
| |
| for (i = 0; i < n; i++) { |
| out[i] = in1[i] ^ in2[i]; |
| } |
| } |
| |
| static int prompeg_create_bitstring(URLContext *h, const uint8_t *buf, int size, |
| uint8_t **bitstring) { |
| PrompegContext *s = h->priv_data; |
| uint8_t *b; |
| |
| if (size < 12 || (buf[0] & 0xc0) != 0x80 || (buf[1] & 0x7f) != 0x21) { |
| av_log(h, AV_LOG_ERROR, "Unsupported stream format (expected MPEG-TS over RTP)\n"); |
| return AVERROR(EINVAL); |
| } |
| if (size != s->packet_size) { |
| av_log(h, AV_LOG_ERROR, "The RTP packet size must be constant (set pkt_size)\n"); |
| return AVERROR(EINVAL); |
| } |
| |
| *bitstring = av_malloc(s->bitstring_size); |
| if (!*bitstring) { |
| av_log(h, AV_LOG_ERROR, "Failed to allocate the bitstring buffer\n"); |
| return AVERROR(ENOMEM); |
| } |
| b = *bitstring; |
| |
| // P, X, CC |
| b[0] = buf[0] & 0x3f; |
| // M, PT |
| b[1] = buf[1]; |
| // Timestamp |
| b[2] = buf[4]; |
| b[3] = buf[5]; |
| b[4] = buf[6]; |
| b[5] = buf[7]; |
| /* |
| * length_recovery: the unsigned network-ordered sum of lengths of CSRC, |
| * padding, extension and media payload |
| */ |
| AV_WB16(b + 6, s->length_recovery); |
| // Payload |
| memcpy(b + 8, buf + 12, s->length_recovery); |
| |
| return 0; |
| } |
| |
| static int prompeg_write_fec(URLContext *h, PrompegFec *fec, uint8_t type) { |
| PrompegContext *s = h->priv_data; |
| URLContext *hd; |
| uint8_t *buf = s->rtp_buf; // zero-filled |
| uint8_t *b = fec->bitstring; |
| uint16_t sn; |
| int ret; |
| |
| sn = type == PROMPEG_FEC_COL ? ++s->rtp_col_sn : ++s->rtp_row_sn; |
| |
| // V, P, X, CC |
| buf[0] = 0x80 | (b[0] & 0x3f); |
| // M, PT |
| buf[1] = (b[1] & 0x80) | PROMPEG_RTP_PT; |
| // SN |
| AV_WB16(buf + 2, sn); |
| // TS |
| AV_WB32(buf + 4, fec->ts); |
| // CSRC=0 |
| //AV_WB32(buf + 8, 0); |
| // SNBase low bits |
| AV_WB16(buf + 12, fec->sn); |
| // Length recovery |
| buf[14] = b[6]; |
| buf[15] = b[7]; |
| // E=1, PT recovery |
| buf[16] = 0x80 | b[1]; |
| // Mask=0 |
| //buf[17] = 0x0; |
| //buf[18] = 0x0; |
| //buf[19] = 0x0; |
| // TS recovery |
| buf[20] = b[2]; |
| buf[21] = b[3]; |
| buf[22] = b[4]; |
| buf[23] = b[5]; |
| // X=0, D, type=0, index=0 |
| buf[24] = type == PROMPEG_FEC_COL ? 0x0 : 0x40; |
| // offset |
| buf[25] = type == PROMPEG_FEC_COL ? s->l : 0x1; |
| // NA |
| buf[26] = type == PROMPEG_FEC_COL ? s->d : s->l; |
| // SNBase ext bits=0 |
| //buf[27] = 0x0; |
| // Payload |
| memcpy(buf + 28, b + 8, s->length_recovery); |
| |
| hd = type == PROMPEG_FEC_COL ? s->fec_col_hd : s->fec_row_hd; |
| ret = ffurl_write(hd, buf, s->rtp_buf_size); |
| return ret; |
| } |
| |
| static int prompeg_open(URLContext *h, const char *uri, int flags) { |
| PrompegContext *s = h->priv_data; |
| AVDictionary *udp_opts = NULL; |
| int rtp_port; |
| char hostname[256]; |
| char buf[1024]; |
| |
| s->fec_col_hd = NULL; |
| s->fec_row_hd = NULL; |
| |
| if (s->l * s->d > 100) { |
| av_log(h, AV_LOG_ERROR, "L * D must be <= 100\n"); |
| return AVERROR(EINVAL); |
| } |
| |
| av_url_split(NULL, 0, NULL, 0, hostname, sizeof (hostname), &rtp_port, |
| NULL, 0, uri); |
| |
| if (rtp_port < 1 || rtp_port > UINT16_MAX - 4) { |
| av_log(h, AV_LOG_ERROR, "Invalid RTP base port %d\n", rtp_port); |
| return AVERROR(EINVAL); |
| } |
| |
| if (s->ttl > 0) { |
| av_dict_set_int(&udp_opts, "ttl", s->ttl, 0); |
| } |
| |
| ff_url_join(buf, sizeof (buf), "udp", NULL, hostname, rtp_port + 2, NULL); |
| if (ffurl_open_whitelist(&s->fec_col_hd, buf, flags, &h->interrupt_callback, |
| &udp_opts, h->protocol_whitelist, h->protocol_blacklist, h) < 0) |
| goto fail; |
| ff_url_join(buf, sizeof (buf), "udp", NULL, hostname, rtp_port + 4, NULL); |
| if (ffurl_open_whitelist(&s->fec_row_hd, buf, flags, &h->interrupt_callback, |
| &udp_opts, h->protocol_whitelist, h->protocol_blacklist, h) < 0) |
| goto fail; |
| |
| h->max_packet_size = s->fec_col_hd->max_packet_size; |
| s->init = 1; |
| |
| av_dict_free(&udp_opts); |
| av_log(h, AV_LOG_INFO, "ProMPEG CoP#3-R2 FEC L=%d D=%d\n", s->l, s->d); |
| return 0; |
| |
| fail: |
| ffurl_closep(&s->fec_col_hd); |
| ffurl_closep(&s->fec_row_hd); |
| av_dict_free(&udp_opts); |
| return AVERROR(EIO); |
| } |
| |
| static int prompeg_init(URLContext *h, const uint8_t *buf, int size) { |
| PrompegContext *s = h->priv_data; |
| uint32_t seed; |
| int i; |
| |
| s->fec_arr = NULL; |
| s->rtp_buf = NULL; |
| |
| if (size < 12 || size > UINT16_MAX + 12) { |
| av_log(h, AV_LOG_ERROR, "Invalid RTP packet size\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| s->packet_idx = 0; |
| s->packet_idx_max = s->l * s->d; |
| s->packet_size = size; |
| s->length_recovery = size - 12; |
| s->rtp_buf_size = 28 + s->length_recovery; // 12 + 16: RTP + FEC headers |
| s->bitstring_size = 8 + s->length_recovery; // 8: P, X, CC, M, PT, SN, TS |
| s->fec_arr_len = 1 + 2 * s->l; // row + column tmp + column out |
| |
| if (h->flags & AVFMT_FLAG_BITEXACT) { |
| s->rtp_col_sn = 0; |
| s->rtp_row_sn = 0; |
| } else { |
| seed = av_get_random_seed(); |
| s->rtp_col_sn = seed & 0x0fff; |
| s->rtp_row_sn = (seed >> 16) & 0x0fff; |
| } |
| |
| s->fec_arr = av_malloc_array(s->fec_arr_len, sizeof (PrompegFec*)); |
| if (!s->fec_arr) { |
| goto fail; |
| } |
| for (i = 0; i < s->fec_arr_len; i++) { |
| s->fec_arr[i] = av_malloc(sizeof (PrompegFec)); |
| if (!s->fec_arr[i]) { |
| goto fail; |
| } |
| s->fec_arr[i]->bitstring = av_malloc_array(s->bitstring_size, sizeof (uint8_t)); |
| if (!s->fec_arr[i]->bitstring) { |
| av_freep(&s->fec_arr[i]); |
| goto fail; |
| } |
| } |
| s->fec_row = *s->fec_arr; |
| s->fec_col = s->fec_arr + 1; |
| s->fec_col_tmp = s->fec_arr + 1 + s->l; |
| |
| s->rtp_buf = av_malloc_array(s->rtp_buf_size, sizeof (uint8_t)); |
| if (!s->rtp_buf) { |
| goto fail; |
| } |
| memset(s->rtp_buf, 0, s->rtp_buf_size); |
| |
| s->init = 0; |
| s->first = 1; |
| |
| return 0; |
| |
| fail: |
| av_log(h, AV_LOG_ERROR, "Failed to allocate the FEC buffer\n"); |
| return AVERROR(ENOMEM); |
| } |
| |
| static int prompeg_write(URLContext *h, const uint8_t *buf, int size) { |
| PrompegContext *s = h->priv_data; |
| PrompegFec *fec_tmp; |
| uint8_t *bitstring = NULL; |
| int col_idx, col_out_idx, row_idx; |
| int ret = 0; |
| |
| if (s->init && ((ret = prompeg_init(h, buf, size)) < 0)) |
| goto end; |
| |
| if ((ret = prompeg_create_bitstring(h, buf, size, &bitstring)) < 0) |
| goto end; |
| |
| col_idx = s->packet_idx % s->l; |
| row_idx = s->packet_idx / s->l % s->d; |
| |
| // FEC' (row) send block-aligned, xor |
| if (col_idx == 0) { |
| if (!s->first || s->packet_idx > 0) { |
| if ((ret = prompeg_write_fec(h, s->fec_row, PROMPEG_FEC_ROW)) < 0) |
| goto end; |
| } |
| memcpy(s->fec_row->bitstring, bitstring, s->bitstring_size); |
| s->fec_row->sn = AV_RB16(buf + 2); |
| s->fec_row->ts = AV_RB32(buf + 4); |
| } else { |
| xor_fast(s->fec_row->bitstring, bitstring, s->fec_row->bitstring, |
| s->bitstring_size); |
| } |
| |
| // FEC (column) xor |
| if (row_idx == 0) { |
| if (!s->first) { |
| // swap fec_col and fec_col_tmp |
| fec_tmp = s->fec_col[col_idx]; |
| s->fec_col[col_idx] = s->fec_col_tmp[col_idx]; |
| s->fec_col_tmp[col_idx] = fec_tmp; |
| } |
| memcpy(s->fec_col_tmp[col_idx]->bitstring, bitstring, s->bitstring_size); |
| s->fec_col_tmp[col_idx]->sn = AV_RB16(buf + 2); |
| s->fec_col_tmp[col_idx]->ts = AV_RB32(buf + 4); |
| } else { |
| xor_fast(s->fec_col_tmp[col_idx]->bitstring, bitstring, |
| s->fec_col_tmp[col_idx]->bitstring, s->bitstring_size); |
| } |
| |
| // FEC (column) send block-aligned |
| if (!s->first && s->packet_idx % s->d == 0) { |
| col_out_idx = s->packet_idx / s->d; |
| if ((ret = prompeg_write_fec(h, s->fec_col[col_out_idx], PROMPEG_FEC_COL)) < 0) |
| goto end; |
| } |
| |
| if (++s->packet_idx >= s->packet_idx_max) { |
| s->packet_idx = 0; |
| if (s->first) |
| s->first = 0; |
| } |
| |
| ret = size; |
| |
| end: |
| av_free(bitstring); |
| return ret; |
| } |
| |
| static int prompeg_close(URLContext *h) { |
| PrompegContext *s = h->priv_data; |
| int i; |
| |
| ffurl_closep(&s->fec_col_hd); |
| 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, |
| }; |