FFmpeg
rtpdec_mpa_robust.c
Go to the documentation of this file.
1 /*
2  * RTP parser for loss tolerant payload format for MP3 audio (RFC 5219)
3  * Copyright (c) 2015 Gilles Chanteperdrix <gch@xenomai.org>
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/attributes.h"
23 #include "libavutil/intreadwrite.h"
24 
25 #include "avio_internal.h"
26 #include "rtpdec_formats.h"
27 
28 struct PayloadContext {
29  unsigned adu_size;
30  unsigned cur_size;
31  uint32_t timestamp;
35 };
36 
38 {
40  av_free(data->split_buf);
41 }
42 
44  const uint8_t *buf, int len,
45  unsigned *adu_size, unsigned *cont)
46 {
47  unsigned header_size;
48 
49  if (len < 2) {
50  av_log(ctx, AV_LOG_ERROR, "Invalid %d bytes packet\n", len);
51  return AVERROR_INVALIDDATA;
52  }
53 
54  *cont = !!(buf[0] & 0x80);
55  if (!(buf[0] & 0x40)) {
56  header_size = 1;
57  *adu_size = buf[0] & ~0xc0;
58  } else {
59  header_size = 2;
60  *adu_size = AV_RB16(buf) & ~0xc000;
61  }
62 
63  return header_size;
64 }
65 
67  AVStream *st, AVPacket *pkt,
68  uint32_t *timestamp, const uint8_t *buf,
69  int len, uint16_t seq, int flags)
70 {
71  unsigned adu_size, continuation;
72  int err, header_size;
73 
74  if (!buf) {
75  buf = &data->split_buf[data->split_pos];
76  len = data->split_buf_size - data->split_pos;
77 
78  header_size = mpa_robust_parse_rtp_header(ctx, buf, len, &adu_size,
79  &continuation);
80  if (header_size < 0) {
81  av_freep(&data->split_buf);
82  return header_size;
83  }
84  buf += header_size;
85  len -= header_size;
86 
87  if (continuation || adu_size > len) {
88  av_freep(&data->split_buf);
89  av_log(ctx, AV_LOG_ERROR, "Invalid frame\n");
90  return AVERROR_INVALIDDATA;
91  }
92 
93  if (av_new_packet(pkt, adu_size)) {
94  av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
95  return AVERROR(ENOMEM);
96  }
97 
98  pkt->stream_index = st->index;
99  memcpy(pkt->data, buf, adu_size);
100 
101  data->split_pos += header_size + adu_size;
102 
103  if (data->split_pos == data->split_buf_size) {
104  av_freep(&data->split_buf);
105  return 0;
106  }
107 
108  return 1;
109  }
110 
111 
112  header_size = mpa_robust_parse_rtp_header(ctx, buf, len, &adu_size,
113  &continuation);
114  if (header_size < 0)
115  return header_size;
116 
117  buf += header_size;
118  len -= header_size;
119 
120  if (!continuation && adu_size <= len) {
121  /* One or more complete frames */
122 
123  if (av_new_packet(pkt, adu_size)) {
124  av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
125  return AVERROR(ENOMEM);
126  }
127 
128  pkt->stream_index = st->index;
129  memcpy(pkt->data, buf, adu_size);
130 
131  buf += adu_size;
132  len -= adu_size;
133  if (len) {
134  data->split_buf_size = len;
135  data->split_buf = av_malloc(data->split_buf_size);
136  data->split_pos = 0;
137  if (!data->split_buf) {
138  av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
139  av_packet_unref(pkt);
140  return AVERROR(ENOMEM);
141  }
142  memcpy(data->split_buf, buf, data->split_buf_size);
143  return 1;
144  }
145  return 0;
146  } else if (!continuation) { /* && adu_size > len */
147  /* First fragment */
148  ffio_free_dyn_buf(&data->fragment);
149 
150  data->adu_size = adu_size;
151  data->cur_size = len;
152  data->timestamp = *timestamp;
153 
154  err = avio_open_dyn_buf(&data->fragment);
155  if (err < 0)
156  return err;
157 
158  avio_write(data->fragment, buf, len);
159  return AVERROR(EAGAIN);
160  }
161  /* else continuation == 1 */
162 
163  /* Fragment other than first */
164  if (!data->fragment) {
165  av_log(ctx, AV_LOG_WARNING,
166  "Received packet without a start fragment; dropping.\n");
167  return AVERROR(EAGAIN);
168  }
169  if (adu_size != data->adu_size ||
170  data->timestamp != *timestamp) {
171  ffio_free_dyn_buf(&data->fragment);
172  av_log(ctx, AV_LOG_ERROR, "Invalid packet received\n");
173  return AVERROR_INVALIDDATA;
174  }
175 
176  avio_write(data->fragment, buf, len);
177  data->cur_size += len;
178 
179  if (data->cur_size < data->adu_size)
180  return AVERROR(EAGAIN);
181 
182  err = ff_rtp_finalize_packet(pkt, &data->fragment, st->index);
183  if (err < 0) {
184  av_log(ctx, AV_LOG_ERROR,
185  "Error occurred when getting fragment buffer.\n");
186  return err;
187  }
188 
189  return 0;
190 }
191 
193  .enc_name = "mpa-robust",
194  .codec_type = AVMEDIA_TYPE_AUDIO,
195  .codec_id = AV_CODEC_ID_MP3ADU,
196  .need_parsing = AVSTREAM_PARSE_HEADERS,
197  .priv_data_size = sizeof(PayloadContext),
198  .close = mpa_robust_close_context,
200 };
AVPacket pkt
Definition: rtpdec_qt.c:37
Bytestream IO Context.
Definition: avio.h:161
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
RTP/JPEG specific private data.
Definition: rdt.c:83
int index
stream index in AVFormatContext
Definition: avformat.h:882
const RTPDynamicProtocolHandler ff_mpeg_audio_robust_dynamic_handler
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_RB16
Definition: bytestream.h:87
int avio_open_dyn_buf(AVIOContext **s)
Open a write only memory stream.
Definition: aviobuf.c:1391
Macro definitions for various function/variable attributes.
Format I/O context.
Definition: avformat.h:1358
static int mpa_robust_parse_rtp_header(AVFormatContext *ctx, const uint8_t *buf, int len, unsigned *adu_size, unsigned *cont)
uint8_t
#define av_malloc(s)
uint8_t * data
Definition: avcodec.h:1477
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:218
#define av_log(a,...)
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:86
uint32_t timestamp
current frame timestamp
Definition: rtpdec_ac3.c:31
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
Only parse headers, do not repack.
Definition: avformat.h:801
AVFormatContext * ctx
Definition: movenc.c:48
static void mpa_robust_close_context(PayloadContext *data)
void ffio_free_dyn_buf(AVIOContext **s)
Free a dynamic buffer.
Definition: aviobuf.c:1450
Stream structure.
Definition: avformat.h:881
AVIOContext * fragment
buffer for split payloads
Definition: rtpdec_ac3.c:32
static int mpa_robust_parse_packet(AVFormatContext *ctx, PayloadContext *data, AVStream *st, AVPacket *pkt, uint32_t *timestamp, const uint8_t *buf, int len, uint16_t seq, int flags)
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:599
uint8_t * buf
the temporary storage buffer
Definition: rtpdec_asf.c:183
const char * enc_name
Definition: rtpdec.h:116
#define flags(name, subs,...)
Definition: cbs_av1.c:561
int ff_rtp_finalize_packet(AVPacket *pkt, AVIOContext **dyn_buf, int stream_idx)
Close the dynamic buffer and make a packet from it.
Definition: rtpdec.c:927
static int parse_packet(AVFormatContext *s, AVPacket *pkt, int stream_index)
Parse a packet, add all split parts to parse_queue.
Definition: utils.c:1438
#define av_free(p)
#define av_freep(p)
int stream_index
Definition: avcodec.h:1479
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
This structure stores compressed data.
Definition: avcodec.h:1454