FFmpeg/libavformat/rtpdec_xiph.c
Andreas Rheinhardt c1e439d7e9 avformat: Forward errors where possible
It is not uncommon to find code where the caller thinks to know better
what the return value should be than the callee. E.g. something like
"if (av_new_packet(pkt, size) < 0) return AVERROR(ENOMEM);". This commit
changes several instances of this to instead forward the actual error.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2019-12-12 19:25:33 +01:00

389 lines
13 KiB
C

/*
* Xiph RTP Protocols
* Copyright (c) 2009 Colin McQuillian
* Copyright (c) 2010 Josh Allmann
*
* 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
*/
/**
* @file
* @brief Xiph / RTP Code
* @author Colin McQuillan <m.niloc@gmail.com>
* @author Josh Allmann <joshua.allmann@gmail.com>
*/
#include "libavutil/attributes.h"
#include "libavutil/avassert.h"
#include "libavutil/avstring.h"
#include "libavutil/base64.h"
#include "libavcodec/bytestream.h"
#include "avio_internal.h"
#include "internal.h"
#include "rtpdec.h"
#include "rtpdec_formats.h"
/**
* RTP/Xiph specific private data.
*/
struct PayloadContext {
unsigned ident; ///< 24-bit stream configuration identifier
uint32_t timestamp;
AVIOContext* fragment; ///< buffer for split payloads
uint8_t *split_buf;
int split_pos, split_buf_len, split_buf_size;
int split_pkts;
};
static void xiph_close_context(PayloadContext * data)
{
ffio_free_dyn_buf(&data->fragment);
av_freep(&data->split_buf);
}
static int xiph_handle_packet(AVFormatContext *ctx, PayloadContext *data,
AVStream *st, AVPacket *pkt, uint32_t *timestamp,
const uint8_t *buf, int len, uint16_t seq,
int flags)
{
int ident, fragmented, tdt, num_pkts, pkt_len, ret;
if (!buf) {
if (!data->split_buf || data->split_pos + 2 > data->split_buf_len ||
data->split_pkts <= 0) {
av_log(ctx, AV_LOG_ERROR, "No more data to return\n");
return AVERROR_INVALIDDATA;
}
pkt_len = AV_RB16(data->split_buf + data->split_pos);
data->split_pos += 2;
if (pkt_len > data->split_buf_len - data->split_pos) {
av_log(ctx, AV_LOG_ERROR, "Not enough data to return\n");
return AVERROR_INVALIDDATA;
}
if ((ret = av_new_packet(pkt, pkt_len)) < 0) {
av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
return ret;
}
pkt->stream_index = st->index;
memcpy(pkt->data, data->split_buf + data->split_pos, pkt_len);
data->split_pos += pkt_len;
data->split_pkts--;
return data->split_pkts > 0;
}
if (len < 6 || len > INT_MAX/2) {
av_log(ctx, AV_LOG_ERROR, "Invalid %d byte packet\n", len);
return AVERROR_INVALIDDATA;
}
// read xiph rtp headers
ident = AV_RB24(buf);
fragmented = buf[3] >> 6;
tdt = (buf[3] >> 4) & 3;
num_pkts = buf[3] & 0xf;
pkt_len = AV_RB16(buf + 4);
if (pkt_len > len - 6) {
av_log(ctx, AV_LOG_ERROR,
"Invalid packet length %d in %d byte packet\n", pkt_len,
len);
return AVERROR_INVALIDDATA;
}
if (ident != data->ident) {
avpriv_report_missing_feature(ctx, "Xiph SDP configuration change");
return AVERROR_PATCHWELCOME;
}
if (tdt) {
avpriv_report_missing_feature(ctx,
"RTP Xiph packet settings (%d,%d,%d)",
fragmented, tdt, num_pkts);
return AVERROR_PATCHWELCOME;
}
buf += 6; // move past header bits
len -= 6;
if (fragmented == 0) {
if ((ret = av_new_packet(pkt, pkt_len)) < 0) {
av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
return ret;
}
pkt->stream_index = st->index;
memcpy(pkt->data, buf, pkt_len);
buf += pkt_len;
len -= pkt_len;
num_pkts--;
if (num_pkts > 0) {
if (len > data->split_buf_size || !data->split_buf) {
av_freep(&data->split_buf);
data->split_buf_size = 2 * len;
data->split_buf = av_malloc(data->split_buf_size);
if (!data->split_buf) {
av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
av_packet_unref(pkt);
return AVERROR(ENOMEM);
}
}
memcpy(data->split_buf, buf, len);
data->split_buf_len = len;
data->split_pos = 0;
data->split_pkts = num_pkts;
return 1;
}
return 0;
} else if (fragmented == 1) {
// start of xiph data fragment
int res;
// end packet has been lost somewhere, so drop buffered data
ffio_free_dyn_buf(&data->fragment);
if((res = avio_open_dyn_buf(&data->fragment)) < 0)
return res;
avio_write(data->fragment, buf, pkt_len);
data->timestamp = *timestamp;
} else {
av_assert1(fragmented < 4);
if (data->timestamp != *timestamp) {
// skip if fragmented timestamp is incorrect;
// a start packet has been lost somewhere
ffio_free_dyn_buf(&data->fragment);
av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match!\n");
return AVERROR_INVALIDDATA;
}
if (!data->fragment) {
av_log(ctx, AV_LOG_WARNING,
"Received packet without a start fragment; dropping.\n");
return AVERROR(EAGAIN);
}
// copy data to fragment buffer
avio_write(data->fragment, buf, pkt_len);
if (fragmented == 3) {
// end of xiph data packet
int ret = ff_rtp_finalize_packet(pkt, &data->fragment, st->index);
if (ret < 0) {
av_log(ctx, AV_LOG_ERROR,
"Error occurred when getting fragment buffer.");
return ret;
}
return 0;
}
}
return AVERROR(EAGAIN);
}
/**
* Length encoding described in RFC5215 section 3.1.1.
*/
static int get_base128(const uint8_t ** buf, const uint8_t * buf_end)
{
int n = 0;
for (; *buf < buf_end; ++*buf) {
n <<= 7;
n += **buf & 0x7f;
if (!(**buf & 0x80)) {
++*buf;
return n;
}
}
return 0;
}
/**
* Based off parse_packed_headers in Vorbis RTP
*/
static int
parse_packed_headers(AVFormatContext *s,
const uint8_t * packed_headers,
const uint8_t * packed_headers_end,
AVCodecParameters *par, PayloadContext * xiph_data)
{
unsigned num_packed, num_headers, length, length1, length2, extradata_alloc;
int ret;
uint8_t *ptr;
if (packed_headers_end - packed_headers < 9) {
av_log(s, AV_LOG_ERROR,
"Invalid %"PTRDIFF_SPECIFIER" byte packed header.",
packed_headers_end - packed_headers);
return AVERROR_INVALIDDATA;
}
num_packed = bytestream_get_be32(&packed_headers);
xiph_data->ident = bytestream_get_be24(&packed_headers);
length = bytestream_get_be16(&packed_headers);
num_headers = get_base128(&packed_headers, packed_headers_end);
length1 = get_base128(&packed_headers, packed_headers_end);
length2 = get_base128(&packed_headers, packed_headers_end);
if (num_packed != 1 || num_headers > 3) {
avpriv_report_missing_feature(s, "%u packed headers, %u headers",
num_packed, num_headers);
return AVERROR_PATCHWELCOME;
}
if (packed_headers_end - packed_headers != length ||
length1 > length || length2 > length - length1) {
av_log(s, AV_LOG_ERROR,
"Bad packed header lengths (%d,%d,%"PTRDIFF_SPECIFIER",%u)\n", length1,
length2, packed_headers_end - packed_headers, length);
return AVERROR_INVALIDDATA;
}
/* allocate extra space:
* -- length/255 +2 for xiphlacing
* -- one for the '2' marker
* -- AV_INPUT_BUFFER_PADDING_SIZE required */
extradata_alloc = length + length/255 + 3 + AV_INPUT_BUFFER_PADDING_SIZE;
if ((ret = ff_alloc_extradata(par, extradata_alloc)) < 0) {
av_log(s, AV_LOG_ERROR, "Out of memory\n");
return ret;
}
ptr = par->extradata;
*ptr++ = 2;
ptr += av_xiphlacing(ptr, length1);
ptr += av_xiphlacing(ptr, length2);
memcpy(ptr, packed_headers, length);
ptr += length;
par->extradata_size = ptr - par->extradata;
// clear out remaining parts of the buffer
memset(ptr, 0, extradata_alloc - par->extradata_size);
return 0;
}
static int xiph_parse_fmtp_pair(AVFormatContext *s,
AVStream* stream,
PayloadContext *xiph_data,
const char *attr, const char *value)
{
AVCodecParameters *par = stream->codecpar;
int result = 0;
if (!strcmp(attr, "sampling")) {
if (!strcmp(value, "YCbCr-4:2:0")) {
par->format = AV_PIX_FMT_YUV420P;
} else if (!strcmp(value, "YCbCr-4:4:2")) {
par->format = AV_PIX_FMT_YUV422P;
} else if (!strcmp(value, "YCbCr-4:4:4")) {
par->format = AV_PIX_FMT_YUV444P;
} else {
av_log(s, AV_LOG_ERROR,
"Unsupported pixel format %s\n", attr);
return AVERROR_INVALIDDATA;
}
} else if (!strcmp(attr, "width")) {
/* This is an integer between 1 and 1048561
* and MUST be in multiples of 16. */
par->width = atoi(value);
return 0;
} else if (!strcmp(attr, "height")) {
/* This is an integer between 1 and 1048561
* and MUST be in multiples of 16. */
par->height = atoi(value);
return 0;
} else if (!strcmp(attr, "delivery-method")) {
/* Possible values are: inline, in_band, out_band/specific_name. */
return AVERROR_PATCHWELCOME;
} else if (!strcmp(attr, "configuration-uri")) {
/* NOTE: configuration-uri is supported only under 2 conditions:
*--after the delivery-method tag
* --with a delivery-method value of out_band */
return AVERROR_PATCHWELCOME;
} else if (!strcmp(attr, "configuration")) {
/* NOTE: configuration is supported only AFTER the delivery-method tag
* The configuration value is a base64 encoded packed header */
uint8_t *decoded_packet = NULL;
int packet_size;
size_t decoded_alloc = strlen(value) / 4 * 3 + 4;
if (decoded_alloc <= INT_MAX) {
decoded_packet = av_malloc(decoded_alloc);
if (decoded_packet) {
packet_size =
av_base64_decode(decoded_packet, value, decoded_alloc);
result = parse_packed_headers
(s, decoded_packet, decoded_packet + packet_size, par,
xiph_data);
} else {
av_log(s, AV_LOG_ERROR,
"Out of memory while decoding SDP configuration.\n");
result = AVERROR(ENOMEM);
}
} else {
av_log(s, AV_LOG_ERROR, "Packet too large\n");
result = AVERROR_INVALIDDATA;
}
av_free(decoded_packet);
}
return result;
}
static int xiph_parse_sdp_line(AVFormatContext *s, int st_index,
PayloadContext *data, const char *line)
{
const char *p;
if (st_index < 0)
return 0;
if (av_strstart(line, "fmtp:", &p)) {
return ff_parse_fmtp(s, s->streams[st_index], data, p,
xiph_parse_fmtp_pair);
}
return 0;
}
const RTPDynamicProtocolHandler ff_theora_dynamic_handler = {
.enc_name = "theora",
.codec_type = AVMEDIA_TYPE_VIDEO,
.codec_id = AV_CODEC_ID_THEORA,
.priv_data_size = sizeof(PayloadContext),
.parse_sdp_a_line = xiph_parse_sdp_line,
.close = xiph_close_context,
.parse_packet = xiph_handle_packet,
};
const RTPDynamicProtocolHandler ff_vorbis_dynamic_handler = {
.enc_name = "vorbis",
.codec_type = AVMEDIA_TYPE_AUDIO,
.codec_id = AV_CODEC_ID_VORBIS,
.need_parsing = AVSTREAM_PARSE_HEADERS,
.priv_data_size = sizeof(PayloadContext),
.parse_sdp_a_line = xiph_parse_sdp_line,
.close = xiph_close_context,
.parse_packet = xiph_handle_packet,
};