| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | /* | ||
| 2 | * RTP packetization for H.263 video | ||
| 3 | * Copyright (c) 2012 Martin Storsjo | ||
| 4 | * | ||
| 5 | * This file is part of FFmpeg. | ||
| 6 | * | ||
| 7 | * FFmpeg is free software; you can redistribute it and/or | ||
| 8 | * modify it under the terms of the GNU Lesser General Public | ||
| 9 | * License as published by the Free Software Foundation; either | ||
| 10 | * version 2.1 of the License, or (at your option) any later version. | ||
| 11 | * | ||
| 12 | * FFmpeg is distributed in the hope that it will be useful, | ||
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
| 15 | * Lesser General Public License for more details. | ||
| 16 | * | ||
| 17 | * You should have received a copy of the GNU Lesser General Public | ||
| 18 | * License along with FFmpeg; if not, write to the Free Software | ||
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
| 20 | */ | ||
| 21 | |||
| 22 | #include "avformat.h" | ||
| 23 | #include "rtpenc.h" | ||
| 24 | #include "libavcodec/put_bits.h" | ||
| 25 | #include "libavcodec/get_bits.h" | ||
| 26 | |||
| 27 | struct H263Info { | ||
| 28 | int src; | ||
| 29 | int i; | ||
| 30 | int u; | ||
| 31 | int s; | ||
| 32 | int a; | ||
| 33 | int pb; | ||
| 34 | int tr; | ||
| 35 | }; | ||
| 36 | |||
| 37 | struct H263State { | ||
| 38 | int gobn; | ||
| 39 | int mba; | ||
| 40 | int hmv1, vmv1, hmv2, vmv2; | ||
| 41 | int quant; | ||
| 42 | }; | ||
| 43 | |||
| 44 | ✗ | static void send_mode_a(AVFormatContext *s1, const struct H263Info *info, | |
| 45 | const uint8_t *buf, int len, int ebits, int m) | ||
| 46 | { | ||
| 47 | ✗ | RTPMuxContext *s = s1->priv_data; | |
| 48 | PutBitContext pb; | ||
| 49 | |||
| 50 | ✗ | init_put_bits(&pb, s->buf, 32); | |
| 51 | ✗ | put_bits(&pb, 1, 0); /* F - 0, mode A */ | |
| 52 | ✗ | put_bits(&pb, 1, 0); /* P - 0, normal I/P */ | |
| 53 | ✗ | put_bits(&pb, 3, 0); /* SBIT - 0 bits */ | |
| 54 | ✗ | put_bits(&pb, 3, ebits); /* EBIT */ | |
| 55 | ✗ | put_bits(&pb, 3, info->src); /* SRC - source format */ | |
| 56 | ✗ | put_bits(&pb, 1, info->i); /* I - inter/intra */ | |
| 57 | ✗ | put_bits(&pb, 1, info->u); /* U - unrestricted motion vector */ | |
| 58 | ✗ | put_bits(&pb, 1, info->s); /* S - syntax-baesd arithmetic coding */ | |
| 59 | ✗ | put_bits(&pb, 1, info->a); /* A - advanced prediction */ | |
| 60 | ✗ | put_bits(&pb, 4, 0); /* R - reserved */ | |
| 61 | ✗ | put_bits(&pb, 2, 0); /* DBQ - 0 */ | |
| 62 | ✗ | put_bits(&pb, 3, 0); /* TRB - 0 */ | |
| 63 | ✗ | put_bits(&pb, 8, info->tr); /* TR */ | |
| 64 | ✗ | flush_put_bits(&pb); | |
| 65 | ✗ | memcpy(s->buf + 4, buf, len); | |
| 66 | |||
| 67 | ✗ | ff_rtp_send_data(s1, s->buf, len + 4, m); | |
| 68 | ✗ | } | |
| 69 | |||
| 70 | ✗ | static void send_mode_b(AVFormatContext *s1, const struct H263Info *info, | |
| 71 | const struct H263State *state, const uint8_t *buf, | ||
| 72 | int len, int sbits, int ebits, int m) | ||
| 73 | { | ||
| 74 | ✗ | RTPMuxContext *s = s1->priv_data; | |
| 75 | PutBitContext pb; | ||
| 76 | |||
| 77 | ✗ | init_put_bits(&pb, s->buf, 64); | |
| 78 | ✗ | put_bits(&pb, 1, 1); /* F - 1, mode B */ | |
| 79 | ✗ | put_bits(&pb, 1, 0); /* P - 0, mode B */ | |
| 80 | ✗ | put_bits(&pb, 3, sbits); /* SBIT - 0 bits */ | |
| 81 | ✗ | put_bits(&pb, 3, ebits); /* EBIT - 0 bits */ | |
| 82 | ✗ | put_bits(&pb, 3, info->src); /* SRC - source format */ | |
| 83 | ✗ | put_bits(&pb, 5, state->quant); /* QUANT - quantizer for the first MB */ | |
| 84 | ✗ | put_bits(&pb, 5, state->gobn); /* GOBN - GOB number */ | |
| 85 | ✗ | put_bits(&pb, 9, state->mba); /* MBA - MB address */ | |
| 86 | ✗ | put_bits(&pb, 2, 0); /* R - reserved */ | |
| 87 | ✗ | put_bits(&pb, 1, info->i); /* I - inter/intra */ | |
| 88 | ✗ | put_bits(&pb, 1, info->u); /* U - unrestricted motion vector */ | |
| 89 | ✗ | put_bits(&pb, 1, info->s); /* S - syntax-baesd arithmetic coding */ | |
| 90 | ✗ | put_bits(&pb, 1, info->a); /* A - advanced prediction */ | |
| 91 | ✗ | put_bits(&pb, 7, state->hmv1); /* HVM1 - horizontal motion vector 1 */ | |
| 92 | ✗ | put_bits(&pb, 7, state->vmv1); /* VMV1 - vertical motion vector 1 */ | |
| 93 | ✗ | put_bits(&pb, 7, state->hmv2); /* HVM2 - horizontal motion vector 2 */ | |
| 94 | ✗ | put_bits(&pb, 7, state->vmv2); /* VMV2 - vertical motion vector 2 */ | |
| 95 | ✗ | flush_put_bits(&pb); | |
| 96 | ✗ | memcpy(s->buf + 8, buf, len); | |
| 97 | |||
| 98 | ✗ | ff_rtp_send_data(s1, s->buf, len + 8, m); | |
| 99 | ✗ | } | |
| 100 | |||
| 101 | ✗ | void ff_rtp_send_h263_rfc2190(AVFormatContext *s1, const uint8_t *buf, int size, | |
| 102 | const uint8_t *mb_info, int mb_info_size) | ||
| 103 | { | ||
| 104 | ✗ | RTPMuxContext *s = s1->priv_data; | |
| 105 | ✗ | int len, sbits = 0, ebits = 0; | |
| 106 | GetBitContext gb; | ||
| 107 | ✗ | struct H263Info info = { 0 }; | |
| 108 | ✗ | struct H263State state = { 0 }; | |
| 109 | ✗ | int mb_info_pos = 0, mb_info_count = mb_info_size / 12; | |
| 110 | ✗ | const uint8_t *buf_base = buf; | |
| 111 | |||
| 112 | ✗ | s->timestamp = s->cur_timestamp; | |
| 113 | |||
| 114 | ✗ | init_get_bits(&gb, buf, size*8); | |
| 115 | ✗ | if (get_bits(&gb, 22) == 0x20) { /* Picture Start Code */ | |
| 116 | ✗ | info.tr = get_bits(&gb, 8); | |
| 117 | ✗ | skip_bits(&gb, 2); /* PTYPE start, H.261 disambiguation */ | |
| 118 | ✗ | skip_bits(&gb, 3); /* Split screen, document camera, freeze picture release */ | |
| 119 | ✗ | info.src = get_bits(&gb, 3); | |
| 120 | ✗ | info.i = get_bits(&gb, 1); | |
| 121 | ✗ | info.u = get_bits(&gb, 1); | |
| 122 | ✗ | info.s = get_bits(&gb, 1); | |
| 123 | ✗ | info.a = get_bits(&gb, 1); | |
| 124 | ✗ | info.pb = get_bits(&gb, 1); | |
| 125 | } | ||
| 126 | |||
| 127 | ✗ | while (size > 0) { | |
| 128 | ✗ | struct H263State packet_start_state = state; | |
| 129 | ✗ | len = FFMIN(s->max_payload_size - 8, size); | |
| 130 | |||
| 131 | /* Look for a better place to split the frame into packets. */ | ||
| 132 | ✗ | if (len < size) { | |
| 133 | ✗ | const uint8_t *end = ff_h263_find_resync_marker_reverse(buf, | |
| 134 | buf + len); | ||
| 135 | ✗ | len = end - buf; | |
| 136 | ✗ | if (len == s->max_payload_size - 8) { | |
| 137 | /* Skip mb info prior to the start of the current ptr */ | ||
| 138 | ✗ | while (mb_info_pos < mb_info_count) { | |
| 139 | ✗ | uint32_t pos = AV_RL32(&mb_info[12*mb_info_pos])/8; | |
| 140 | ✗ | if (pos >= buf - buf_base) | |
| 141 | ✗ | break; | |
| 142 | ✗ | mb_info_pos++; | |
| 143 | } | ||
| 144 | /* Find the first mb info past the end pointer */ | ||
| 145 | ✗ | while (mb_info_pos + 1 < mb_info_count) { | |
| 146 | ✗ | uint32_t pos = AV_RL32(&mb_info[12*(mb_info_pos + 1)])/8; | |
| 147 | ✗ | if (pos >= end - buf_base) | |
| 148 | ✗ | break; | |
| 149 | ✗ | mb_info_pos++; | |
| 150 | } | ||
| 151 | ✗ | if (mb_info_pos < mb_info_count) { | |
| 152 | ✗ | const uint8_t *ptr = &mb_info[12*mb_info_pos]; | |
| 153 | /* get position in bits in the input packet at which the next info block should be used */ | ||
| 154 | ✗ | uint32_t bit_pos = AV_RL32(ptr); | |
| 155 | /* get position in bytes */ | ||
| 156 | ✗ | uint32_t pos_next_mb_info = (bit_pos + 7)/8; | |
| 157 | /* check if data from the next MB info block should be used */ | ||
| 158 | ✗ | if (pos_next_mb_info <= end - buf_base) { | |
| 159 | ✗ | state.quant = ptr[4]; | |
| 160 | ✗ | state.gobn = ptr[5]; | |
| 161 | ✗ | state.mba = AV_RL16(&ptr[6]); | |
| 162 | ✗ | state.hmv1 = (int8_t) ptr[8]; | |
| 163 | ✗ | state.vmv1 = (int8_t) ptr[9]; | |
| 164 | ✗ | state.hmv2 = (int8_t) ptr[10]; | |
| 165 | ✗ | state.vmv2 = (int8_t) ptr[11]; | |
| 166 | ✗ | ebits = 8 * pos_next_mb_info - bit_pos; | |
| 167 | ✗ | len = pos_next_mb_info - (buf - buf_base); | |
| 168 | ✗ | mb_info_pos++; | |
| 169 | } | ||
| 170 | } else { | ||
| 171 | ✗ | av_log(s1, AV_LOG_ERROR, "Unable to split H.263 packet, " | |
| 172 | "use -mb_info %d or -ps 1.\n", | ||
| 173 | ✗ | s->max_payload_size - 8); | |
| 174 | } | ||
| 175 | } | ||
| 176 | } | ||
| 177 | |||
| 178 | ✗ | if (size > 2 && !buf[0] && !buf[1]) | |
| 179 | ✗ | send_mode_a(s1, &info, buf, len, ebits, len == size); | |
| 180 | else | ||
| 181 | ✗ | send_mode_b(s1, &info, &packet_start_state, buf, len, sbits, | |
| 182 | ebits, len == size); | ||
| 183 | |||
| 184 | ✗ | if (ebits) { | |
| 185 | ✗ | sbits = 8 - ebits; | |
| 186 | ✗ | len--; | |
| 187 | } else { | ||
| 188 | ✗ | sbits = 0; | |
| 189 | } | ||
| 190 | ✗ | buf += len; | |
| 191 | ✗ | size -= len; | |
| 192 | ✗ | ebits = 0; | |
| 193 | } | ||
| 194 | ✗ | } | |
| 195 |