| /* |
| * RTP JPEG-compressed video Packetizer, RFC 2435 |
| * Copyright (c) 2012 Samuel Pitoiset |
| * |
| * 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 |
| */ |
| |
| #include "libavcodec/bytestream.h" |
| #include "libavcodec/mjpeg.h" |
| #include "libavutil/intreadwrite.h" |
| #include "rtpenc.h" |
| |
| void ff_rtp_send_jpeg(AVFormatContext *s1, const uint8_t *buf, int size) |
| { |
| RTPMuxContext *s = s1->priv_data; |
| const uint8_t *qtables = NULL; |
| int nb_qtables = 0; |
| uint8_t type = 1; /* default pixel format is AV_PIX_FMT_YUVJ420P */ |
| uint8_t w, h; |
| uint8_t *p; |
| int off = 0; /* fragment offset of the current JPEG frame */ |
| int len; |
| int i; |
| |
| s->buf_ptr = s->buf; |
| s->timestamp = s->cur_timestamp; |
| |
| /* convert video pixel dimensions from pixels to blocks */ |
| w = s1->streams[0]->codec->width >> 3; |
| h = s1->streams[0]->codec->height >> 3; |
| |
| /* check if pixel format is not the normal 420 case */ |
| if (s1->streams[0]->codec->pix_fmt == AV_PIX_FMT_YUVJ422P) { |
| type = 0; |
| } else if (s1->streams[0]->codec->pix_fmt == AV_PIX_FMT_YUVJ420P) { |
| type = 1; |
| } else { |
| av_log(s1, AV_LOG_ERROR, "Unsupported pixel format\n"); |
| return; |
| } |
| |
| /* preparse the header for getting some infos */ |
| for (i = 0; i < size; i++) { |
| if (buf[i] != 0xff) |
| continue; |
| |
| if (buf[i + 1] == DQT) { |
| if (buf[i + 4]) |
| av_log(s1, AV_LOG_WARNING, |
| "Only 8-bit precision is supported.\n"); |
| |
| /* a quantization table is 64 bytes long */ |
| nb_qtables = AV_RB16(&buf[i + 2]) / 65; |
| if (i + 4 + nb_qtables * 65 > size) { |
| av_log(s1, AV_LOG_ERROR, "Too short JPEG header. Aborted!\n"); |
| return; |
| } |
| |
| qtables = &buf[i + 4]; |
| } else if (buf[i + 1] == SOF0) { |
| if (buf[i + 14] != 17 || buf[i + 17] != 17) { |
| av_log(s1, AV_LOG_ERROR, |
| "Only 1x1 chroma blocks are supported. Aborted!\n"); |
| return; |
| } |
| } else if (buf[i + 1] == SOS) { |
| /* SOS is last marker in the header */ |
| i += AV_RB16(&buf[i + 2]) + 2; |
| break; |
| } |
| } |
| |
| /* skip JPEG header */ |
| buf += i; |
| size -= i; |
| |
| for (i = size - 2; i >= 0; i--) { |
| if (buf[i] == 0xff && buf[i + 1] == EOI) { |
| /* Remove the EOI marker */ |
| size = i; |
| break; |
| } |
| } |
| |
| p = s->buf_ptr; |
| while (size > 0) { |
| int hdr_size = 8; |
| |
| if (off == 0 && nb_qtables) |
| hdr_size += 4 + 64 * nb_qtables; |
| |
| /* payload max in one packet */ |
| len = FFMIN(size, s->max_payload_size - hdr_size); |
| |
| /* set main header */ |
| bytestream_put_byte(&p, 0); |
| bytestream_put_be24(&p, off); |
| bytestream_put_byte(&p, type); |
| bytestream_put_byte(&p, 255); |
| bytestream_put_byte(&p, w); |
| bytestream_put_byte(&p, h); |
| |
| if (off == 0 && nb_qtables) { |
| /* set quantization tables header */ |
| bytestream_put_byte(&p, 0); |
| bytestream_put_byte(&p, 0); |
| bytestream_put_be16(&p, 64 * nb_qtables); |
| |
| for (i = 0; i < nb_qtables; i++) |
| bytestream_put_buffer(&p, &qtables[65 * i + 1], 64); |
| } |
| |
| /* copy payload data */ |
| memcpy(p, buf, len); |
| |
| /* marker bit is last packet in frame */ |
| ff_rtp_send_data(s1, s->buf, len + hdr_size, size == len); |
| |
| buf += len; |
| size -= len; |
| off += len; |
| p = s->buf; |
| } |
| } |