diff options
Diffstat (limited to 'libavformat/rtpenc_h263_rfc2190.c')
-rw-r--r-- | libavformat/rtpenc_h263_rfc2190.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/libavformat/rtpenc_h263_rfc2190.c b/libavformat/rtpenc_h263_rfc2190.c new file mode 100644 index 0000000000..305c1a27c8 --- /dev/null +++ b/libavformat/rtpenc_h263_rfc2190.c @@ -0,0 +1,104 @@ +/* + * RTP packetization for H.263 video + * Copyright (c) 2012 Martin Storsjo + * + * This file is part of Libav. + * + * Libav 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. + * + * Libav 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 Libav; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "avformat.h" +#include "rtpenc.h" +#include "libavcodec/put_bits.h" +#include "libavcodec/get_bits.h" + +struct H263Info { + int src; + int i; + int u; + int s; + int a; + int pb; + int tr; +}; + +static void send_mode_a(AVFormatContext *s1, const struct H263Info *info, + const uint8_t *buf, int len, int m) +{ + RTPMuxContext *s = s1->priv_data; + PutBitContext pb; + + init_put_bits(&pb, s->buf, 32); + put_bits(&pb, 1, 0); /* F - 0, mode A */ + put_bits(&pb, 1, 0); /* P - 0, normal I/P */ + put_bits(&pb, 3, 0); /* SBIT - 0 bits */ + put_bits(&pb, 3, 0); /* EBIT - 0 bits */ + put_bits(&pb, 3, info->src); /* SRC - source format */ + put_bits(&pb, 1, info->i); /* I - inter/intra */ + put_bits(&pb, 1, info->u); /* U - unrestricted motion vector */ + put_bits(&pb, 1, info->s); /* S - syntax-baesd arithmetic coding */ + put_bits(&pb, 1, info->a); /* A - advanced prediction */ + put_bits(&pb, 4, 0); /* R - reserved */ + put_bits(&pb, 2, 0); /* DBQ - 0 */ + put_bits(&pb, 3, 0); /* TRB - 0 */ + put_bits(&pb, 8, info->tr); /* TR */ + flush_put_bits(&pb); + memcpy(s->buf + 4, buf, len); + + ff_rtp_send_data(s1, s->buf, len + 4, m); +} + +void ff_rtp_send_h263_rfc2190(AVFormatContext *s1, const uint8_t *buf, int size) +{ + RTPMuxContext *s = s1->priv_data; + int len; + GetBitContext gb; + struct H263Info info = { 0 }; + + s->timestamp = s->cur_timestamp; + + init_get_bits(&gb, buf, size*8); + if (get_bits(&gb, 22) == 0x20) { /* Picture Start Code */ + info.tr = get_bits(&gb, 8); + skip_bits(&gb, 2); /* PTYPE start, H261 disambiguation */ + skip_bits(&gb, 3); /* Split screen, document camera, freeze picture release */ + info.src = get_bits(&gb, 3); + info.i = get_bits(&gb, 1); + info.u = get_bits(&gb, 1); + info.s = get_bits(&gb, 1); + info.a = get_bits(&gb, 1); + info.pb = get_bits(&gb, 1); + } + + while (size > 0) { + len = FFMIN(s->max_payload_size - 4, size); + + /* Look for a better place to split the frame into packets. */ + if (len < size) { + const uint8_t *end = ff_h263_find_resync_marker_reverse(buf, + buf + len); + len = end - buf; + if (len == s->max_payload_size - 4) + av_log(s1, AV_LOG_WARNING, + "No GOB boundary found within MTU size, splitting at " + "a random boundary\n"); + } + + send_mode_a(s1, &info, buf, len, len == size); + + buf += len; + size -= len; + } +} |