1 /*
2  * RTP packetizer for VC-2 HQ payload format (draft version 1) - experimental
3  * Copyright (c) 2016 Thomas Volkert <thomas@netzeal.de>
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 "libavutil/intreadwrite.h"
23 #include "libavcodec/dirac.h"
24 #include "libavcodec/get_bits.h"
25 #include "libavcodec/golomb.h"
26 
27 #include "avformat.h"
28 #include "rtpenc.h"
29 
30 #define RTP_VC2HQ_PL_HEADER_SIZE             4
31 
32 #define DIRAC_DATA_UNIT_HEADER_SIZE          13
33 #define DIRAC_PIC_NR_SIZE                    4
34 #define DIRAC_RTP_PCODE_HQ_PIC_FRAGMENT      0xEC
35 
send_packet(AVFormatContext * ctx,uint8_t parse_code,int info_hdr_size,const uint8_t * buf,int size,int i,int f,int rtp_m)36 static void send_packet(AVFormatContext *ctx, uint8_t parse_code, int info_hdr_size, const uint8_t *buf, int size, int i, int f, int rtp_m)
37 {
38     RTPMuxContext *rtp_ctx = ctx->priv_data;
39 
40     AV_WB16(&rtp_ctx->buf[0], 0); /* extended sequence number */
41     AV_WB8 (&rtp_ctx->buf[2], i ? (f ? (0x03) : (0x02)) : 0x00); /* flags: interlaced, second field */
42     AV_WB8 (&rtp_ctx->buf[3], parse_code);
43     if (size > 0)
44         memcpy(&rtp_ctx->buf[4 + info_hdr_size], buf, size);
45     ff_rtp_send_data(ctx, rtp_ctx->buf, RTP_VC2HQ_PL_HEADER_SIZE + info_hdr_size + size, rtp_m);
46 }
47 
send_picture(AVFormatContext * ctx,const uint8_t * buf,int size,int interlaced)48 static void send_picture(AVFormatContext *ctx, const uint8_t *buf, int size, int interlaced)
49 {
50     RTPMuxContext *rtp_ctx = ctx->priv_data;
51     GetBitContext gc;
52     int lvl, second_field;
53     uint32_t pic_nr, wavelet_depth, prefix_bytes, size_scaler;
54     uint16_t frag_len;
55     char *info_hdr = &rtp_ctx->buf[4];
56 
57     pic_nr = AV_RB32(&buf[0]);
58     buf += DIRAC_PIC_NR_SIZE;
59     size -= DIRAC_PIC_NR_SIZE;
60     second_field = interlaced && (pic_nr & 0x01);
61 
62     init_get_bits(&gc, buf, 8  * size);
63                     get_interleaved_ue_golomb(&gc); /* wavelet_idx */
64     wavelet_depth = get_interleaved_ue_golomb(&gc);
65                     get_interleaved_ue_golomb(&gc); /* num_x */
66                     get_interleaved_ue_golomb(&gc); /* num_y */
67     prefix_bytes  = get_interleaved_ue_golomb(&gc);
68     size_scaler   = get_interleaved_ue_golomb(&gc);
69     /* pass the quantization matrices */
70     get_interleaved_ue_golomb(&gc);
71     for(lvl = 0; lvl < wavelet_depth; lvl++)
72     {
73         get_interleaved_ue_golomb(&gc);
74         get_interleaved_ue_golomb(&gc);
75         get_interleaved_ue_golomb(&gc);
76     }
77 
78     frag_len = (get_bits_count(&gc) + 7) / 8; /* length of transform parameters */
79 
80     AV_WB32(&info_hdr[ 0], pic_nr);
81     AV_WB16(&info_hdr[ 4], prefix_bytes);
82     AV_WB16(&info_hdr[ 6], size_scaler);
83     AV_WB16(&info_hdr[ 8], frag_len);
84     AV_WB16(&info_hdr[10], 0 /* nr. of slices */);
85     send_packet(ctx, DIRAC_RTP_PCODE_HQ_PIC_FRAGMENT, 12, buf, frag_len, interlaced, second_field, 0);
86     buf += frag_len;
87     size -= frag_len;
88 
89     while (size > 0) {
90         frag_len = FFMIN(rtp_ctx->max_payload_size - 20 /* pl header */, size);
91         AV_WB16(&info_hdr[ 8], frag_len);
92         AV_WB16(&info_hdr[10], 1 /* nr. of slices */);
93         AV_WB16(&info_hdr[12], 0 /* slice x */);
94         AV_WB16(&info_hdr[14], 0 /* slice y */);
95 
96         size -= frag_len;
97         send_packet(ctx, DIRAC_RTP_PCODE_HQ_PIC_FRAGMENT, 16, buf, frag_len, interlaced, second_field, size > 0 ? 0 : 1);
98         buf += frag_len;
99     }
100 }
101 
ff_rtp_send_vc2hq(AVFormatContext * ctx,const uint8_t * frame_buf,int frame_size,int interlaced)102 void ff_rtp_send_vc2hq(AVFormatContext *ctx, const uint8_t *frame_buf, int frame_size, int interlaced)
103 {
104     const uint8_t *end = frame_buf + frame_size;
105     const uint8_t *unit = frame_buf;
106     uint8_t parse_code;
107     uint32_t unit_size;
108 
109     while (unit < end) {
110         parse_code = unit[4];
111         unit_size = AV_RB32(&unit[5]);
112 
113         switch (parse_code) {
114         /* sequence header */
115         /* end of sequence */
116         case DIRAC_PCODE_SEQ_HEADER:
117         case DIRAC_PCODE_END_SEQ:
118             send_packet(ctx, parse_code, 0, unit + DIRAC_DATA_UNIT_HEADER_SIZE, unit_size - DIRAC_DATA_UNIT_HEADER_SIZE, 0, 0, 0);
119             break;
120         /* HQ picture */
121         case DIRAC_PCODE_PICTURE_HQ:
122             send_picture(ctx, unit + DIRAC_DATA_UNIT_HEADER_SIZE, unit_size - DIRAC_DATA_UNIT_HEADER_SIZE, interlaced);
123             break;
124         /* parse codes without specification */
125         case DIRAC_PCODE_AUX:
126         case DIRAC_PCODE_PAD:
127             break;
128         default:
129             avpriv_report_missing_feature(ctx, "VC-2 parse code %d", parse_code);
130             break;
131         }
132         unit += unit_size;
133     }
134 }
135