Go to most recent revision | Details | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4349 | Serge | 1 | /* |
| 2 | * RTP H.263 Depacketizer, RFC 4629 |
||
| 3 | * Copyright (c) 2010 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 "rtpdec_formats.h" |
||
| 24 | #include "libavutil/attributes.h" |
||
| 25 | #include "libavutil/intreadwrite.h" |
||
| 26 | |||
| 27 | static av_cold int h263_init(AVFormatContext *ctx, int st_index, |
||
| 28 | PayloadContext *data) |
||
| 29 | { |
||
| 30 | if (st_index < 0) |
||
| 31 | return 0; |
||
| 32 | ctx->streams[st_index]->need_parsing = AVSTREAM_PARSE_FULL; |
||
| 33 | return 0; |
||
| 34 | } |
||
| 35 | |||
| 36 | int ff_h263_handle_packet(AVFormatContext *ctx, PayloadContext *data, |
||
| 37 | AVStream *st, AVPacket *pkt, uint32_t *timestamp, |
||
| 38 | const uint8_t *buf, int len, uint16_t seq, int flags) |
||
| 39 | { |
||
| 40 | uint8_t *ptr; |
||
| 41 | uint16_t header; |
||
| 42 | int startcode, vrc, picture_header; |
||
| 43 | |||
| 44 | if (len < 2) { |
||
| 45 | av_log(ctx, AV_LOG_ERROR, "Too short H.263 RTP packet\n"); |
||
| 46 | return AVERROR_INVALIDDATA; |
||
| 47 | } |
||
| 48 | |||
| 49 | /* Decode the 16 bit H.263+ payload header, as described in section |
||
| 50 | * 5.1 of RFC 4629. The fields of this header are: |
||
| 51 | * - 5 reserved bits, should be ignored. |
||
| 52 | * - One bit (P, startcode), indicating a picture start, picture segment |
||
| 53 | * start or video sequence end. If set, two zero bytes should be |
||
| 54 | * prepended to the payload. |
||
| 55 | * - One bit (V, vrc), indicating the presence of an 8 bit Video |
||
| 56 | * Redundancy Coding field after this 16 bit header. |
||
| 57 | * - 6 bits (PLEN, picture_header), the length (in bytes) of an extra |
||
| 58 | * picture header, following the VRC field. |
||
| 59 | * - 3 bits (PEBIT), the number of bits to ignore of the last byte |
||
| 60 | * of the extra picture header. (Not used at the moment.) |
||
| 61 | */ |
||
| 62 | header = AV_RB16(buf); |
||
| 63 | startcode = (header & 0x0400) >> 9; |
||
| 64 | vrc = header & 0x0200; |
||
| 65 | picture_header = (header & 0x01f8) >> 3; |
||
| 66 | buf += 2; |
||
| 67 | len -= 2; |
||
| 68 | |||
| 69 | if (vrc) { |
||
| 70 | /* Skip VRC header if present, not used at the moment. */ |
||
| 71 | buf += 1; |
||
| 72 | len -= 1; |
||
| 73 | } |
||
| 74 | if (picture_header) { |
||
| 75 | /* Skip extra picture header if present, not used at the moment. */ |
||
| 76 | buf += picture_header; |
||
| 77 | len -= picture_header; |
||
| 78 | } |
||
| 79 | |||
| 80 | if (len < 0) { |
||
| 81 | av_log(ctx, AV_LOG_ERROR, "Too short H.263 RTP packet\n"); |
||
| 82 | return AVERROR_INVALIDDATA; |
||
| 83 | } |
||
| 84 | |||
| 85 | if (av_new_packet(pkt, len + startcode)) { |
||
| 86 | av_log(ctx, AV_LOG_ERROR, "Out of memory\n"); |
||
| 87 | return AVERROR(ENOMEM); |
||
| 88 | } |
||
| 89 | pkt->stream_index = st->index; |
||
| 90 | ptr = pkt->data; |
||
| 91 | |||
| 92 | if (startcode) { |
||
| 93 | *ptr++ = 0; |
||
| 94 | *ptr++ = 0; |
||
| 95 | } |
||
| 96 | memcpy(ptr, buf, len); |
||
| 97 | |||
| 98 | return 0; |
||
| 99 | } |
||
| 100 | |||
| 101 | RTPDynamicProtocolHandler ff_h263_1998_dynamic_handler = { |
||
| 102 | .enc_name = "H263-1998", |
||
| 103 | .codec_type = AVMEDIA_TYPE_VIDEO, |
||
| 104 | .codec_id = AV_CODEC_ID_H263, |
||
| 105 | .init = h263_init, |
||
| 106 | .parse_packet = ff_h263_handle_packet, |
||
| 107 | }; |
||
| 108 | |||
| 109 | RTPDynamicProtocolHandler ff_h263_2000_dynamic_handler = { |
||
| 110 | .enc_name = "H263-2000", |
||
| 111 | .codec_type = AVMEDIA_TYPE_VIDEO, |
||
| 112 | .codec_id = AV_CODEC_ID_H263, |
||
| 113 | .init = h263_init, |
||
| 114 | .parse_packet = ff_h263_handle_packet, |
||
| 115 | }; |