[deb_ffmpeg.git] / ffmpeg / libavformat / rtpdec_xiph.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 "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 PayloadContext *xiph_new_context(void)
{
    return av_mallocz(sizeof(PayloadContext));
}

static inline void free_fragment_if_needed(PayloadContext * data)
{
    if (data->fragment) {
        uint8_t* p;
        avio_close_dyn_buf(data->fragment, &p);
        av_free(p);
        data->fragment = NULL;
    }
}

static void xiph_free_context(PayloadContext * data)
{
    free_fragment_if_needed(data);
    av_free(data->split_buf);
    av_free(data);
}

static av_cold int xiph_vorbis_init(AVFormatContext *ctx, int st_index,
                                    PayloadContext *data)
{
    if (st_index < 0)
        return 0;
    ctx->streams[st_index]->need_parsing = AVSTREAM_PARSE_HEADERS;
    return 0;
}


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;

    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 (data->split_pos + pkt_len > data->split_buf_len) {
            av_log(ctx, AV_LOG_ERROR, "Not enough data to return\n");
            return AVERROR_INVALIDDATA;
        }
        if (av_new_packet(pkt, pkt_len)) {
            av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
            return AVERROR(ENOMEM);
        }
        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) {
        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) {
        av_log(ctx, AV_LOG_ERROR,
               "Unimplemented Xiph SDP configuration change detected\n");
        return AVERROR_PATCHWELCOME;
    }

    if (tdt) {
        av_log(ctx, AV_LOG_ERROR,
               "Unimplemented RTP Xiph packet settings (%d,%d,%d)\n",
               fragmented, tdt, num_pkts);
        return AVERROR_PATCHWELCOME;
    }

    buf += 6; // move past header bits
    len -= 6;

    if (fragmented == 0) {
        if (av_new_packet(pkt, pkt_len)) {
            av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
            return AVERROR(ENOMEM);
        }
        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_free_packet(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
        free_fragment_if_needed(data);

        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
            free_fragment_if_needed(data);
            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(const uint8_t * packed_headers,
                     const uint8_t * packed_headers_end,
                     AVCodecContext * codec, PayloadContext * xiph_data)
{

    unsigned num_packed, num_headers, length, length1, length2, extradata_alloc;
    uint8_t *ptr;

    if (packed_headers_end - packed_headers < 9) {
        av_log(codec, 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) {
        av_log(codec, AV_LOG_ERROR,
               "Unimplemented number of headers: %d packed headers, %d headers\n",
               num_packed, num_headers);
        return AVERROR_PATCHWELCOME;
    }

    if (packed_headers_end - packed_headers != length ||
        length1 > length || length2 > length - length1) {
        av_log(codec, AV_LOG_ERROR,
               "Bad packed header lengths (%d,%d,%"PTRDIFF_SPECIFIER",%d)\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
     * -- FF_INPUT_BUFFER_PADDING_SIZE required */
    extradata_alloc = length + length/255 + 3 + FF_INPUT_BUFFER_PADDING_SIZE;

    if (ff_alloc_extradata(codec, extradata_alloc)) {
        av_log(codec, AV_LOG_ERROR, "Out of memory\n");
        return AVERROR(ENOMEM);
    }
    ptr = codec->extradata;
    *ptr++ = 2;
    ptr += av_xiphlacing(ptr, length1);
    ptr += av_xiphlacing(ptr, length2);
    memcpy(ptr, packed_headers, length);
    ptr += length;
    codec->extradata_size = ptr - codec->extradata;
    // clear out remaining parts of the buffer
    memset(ptr, 0, extradata_alloc - codec->extradata_size);

    return 0;
}

static int xiph_parse_fmtp_pair(AVFormatContext *s,
                                AVStream* stream,
                                PayloadContext *xiph_data,
                                char *attr, char *value)
{
    AVCodecContext *codec = stream->codec;
    int result = 0;

    if (!strcmp(attr, "sampling")) {
        if (!strcmp(value, "YCbCr-4:2:0")) {
            codec->pix_fmt = AV_PIX_FMT_YUV420P;
        } else if (!strcmp(value, "YCbCr-4:4:2")) {
            codec->pix_fmt = AV_PIX_FMT_YUV422P;
        } else if (!strcmp(value, "YCbCr-4:4:4")) {
            codec->pix_fmt = 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. */
        codec->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. */
        codec->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
                    (decoded_packet, decoded_packet + packet_size, codec,
                    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;
}

RTPDynamicProtocolHandler ff_theora_dynamic_handler = {
    .enc_name         = "theora",
    .codec_type       = AVMEDIA_TYPE_VIDEO,
    .codec_id         = AV_CODEC_ID_THEORA,
    .parse_sdp_a_line = xiph_parse_sdp_line,
    .alloc            = xiph_new_context,
    .free             = xiph_free_context,
    .parse_packet     = xiph_handle_packet
};

RTPDynamicProtocolHandler ff_vorbis_dynamic_handler = {
    .enc_name         = "vorbis",
    .codec_type       = AVMEDIA_TYPE_AUDIO,
    .codec_id         = AV_CODEC_ID_VORBIS,
    .init             = xiph_vorbis_init,
    .parse_sdp_a_line = xiph_parse_sdp_line,
    .alloc            = xiph_new_context,
    .free             = xiph_free_context,
    .parse_packet     = xiph_handle_packet
};
Commit	Line	Data
	1	/*
	2	* Xiph RTP Protocols
	3	* Copyright (c) 2009 Colin McQuillian
	4	* Copyright (c) 2010 Josh Allmann
	5	*
	6	* This file is part of FFmpeg.
	7	*
	8	* FFmpeg is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU Lesser General Public
	10	* License as published by the Free Software Foundation; either
	11	* version 2.1 of the License, or (at your option) any later version.
	12	*
	13	* FFmpeg is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	16	* Lesser General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU Lesser General Public
	19	* License along with FFmpeg; if not, write to the Free Software
	20	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	21	*/
	22
	23	/**
	24	* @file
	25	* @brief Xiph / RTP Code
	26	* @author Colin McQuillan <m.niloc@gmail.com>
	27	* @author Josh Allmann <joshua.allmann@gmail.com>
	28	*/
	29
	30	#include "libavutil/attributes.h"
	31	#include "libavutil/avassert.h"
	32	#include "libavutil/avstring.h"
	33	#include "libavutil/base64.h"
	34	#include "libavcodec/bytestream.h"
	35
	36	#include "internal.h"
	37	#include "rtpdec.h"
	38	#include "rtpdec_formats.h"
	39
	40	/**
	41	* RTP/Xiph specific private data.
	42	*/
	43	struct PayloadContext {
	44	unsigned ident; ///< 24-bit stream configuration identifier
	45	uint32_t timestamp;
	46	AVIOContext* fragment; ///< buffer for split payloads
	47	uint8_t *split_buf;
	48	int split_pos, split_buf_len, split_buf_size;
	49	int split_pkts;
	50	};
	51
	52	static PayloadContext *xiph_new_context(void)
	53	{
	54	return av_mallocz(sizeof(PayloadContext));
	55	}
	56
	57	static inline void free_fragment_if_needed(PayloadContext * data)
	58	{
	59	if (data->fragment) {
	60	uint8_t* p;
	61	avio_close_dyn_buf(data->fragment, &p);
	62	av_free(p);
	63	data->fragment = NULL;
	64	}
	65	}
	66
	67	static void xiph_free_context(PayloadContext * data)
	68	{
	69	free_fragment_if_needed(data);
	70	av_free(data->split_buf);
	71	av_free(data);
	72	}
	73
	74	static av_cold int xiph_vorbis_init(AVFormatContext *ctx, int st_index,
	75	PayloadContext *data)
	76	{
	77	if (st_index < 0)
	78	return 0;
	79	ctx->streams[st_index]->need_parsing = AVSTREAM_PARSE_HEADERS;
	80	return 0;
	81	}
	82
	83
	84	static int xiph_handle_packet(AVFormatContext ctx, PayloadContext data,
	85	AVStream st, AVPacket pkt, uint32_t *timestamp,
	86	const uint8_t *buf, int len, uint16_t seq,
	87	int flags)
	88	{
	89
	90	int ident, fragmented, tdt, num_pkts, pkt_len;
	91
	92	if (!buf) {
	93	if (!data->split_buf \|\| data->split_pos + 2 > data->split_buf_len \|\|
	94	data->split_pkts <= 0) {
	95	av_log(ctx, AV_LOG_ERROR, "No more data to return\n");
	96	return AVERROR_INVALIDDATA;
	97	}
	98	pkt_len = AV_RB16(data->split_buf + data->split_pos);
	99	data->split_pos += 2;
	100	if (data->split_pos + pkt_len > data->split_buf_len) {
	101	av_log(ctx, AV_LOG_ERROR, "Not enough data to return\n");
	102	return AVERROR_INVALIDDATA;
	103	}
	104	if (av_new_packet(pkt, pkt_len)) {
	105	av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
	106	return AVERROR(ENOMEM);
	107	}
	108	pkt->stream_index = st->index;
	109	memcpy(pkt->data, data->split_buf + data->split_pos, pkt_len);
	110	data->split_pos += pkt_len;
	111	data->split_pkts--;
	112	return data->split_pkts > 0;
	113	}
	114
	115	if (len < 6) {
	116	av_log(ctx, AV_LOG_ERROR, "Invalid %d byte packet\n", len);
	117	return AVERROR_INVALIDDATA;
	118	}
	119
	120	// read xiph rtp headers
	121	ident = AV_RB24(buf);
	122	fragmented = buf[3] >> 6;
	123	tdt = (buf[3] >> 4) & 3;
	124	num_pkts = buf[3] & 0xf;
	125	pkt_len = AV_RB16(buf + 4);
	126
	127	if (pkt_len > len - 6) {
	128	av_log(ctx, AV_LOG_ERROR,
	129	"Invalid packet length %d in %d byte packet\n", pkt_len,
	130	len);
	131	return AVERROR_INVALIDDATA;
	132	}
	133
	134	if (ident != data->ident) {
	135	av_log(ctx, AV_LOG_ERROR,
	136	"Unimplemented Xiph SDP configuration change detected\n");
	137	return AVERROR_PATCHWELCOME;
	138	}
	139
	140	if (tdt) {
	141	av_log(ctx, AV_LOG_ERROR,
	142	"Unimplemented RTP Xiph packet settings (%d,%d,%d)\n",
	143	fragmented, tdt, num_pkts);
	144	return AVERROR_PATCHWELCOME;
	145	}
	146
	147	buf += 6; // move past header bits
	148	len -= 6;
	149
	150	if (fragmented == 0) {
	151	if (av_new_packet(pkt, pkt_len)) {
	152	av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
	153	return AVERROR(ENOMEM);
	154	}
	155	pkt->stream_index = st->index;
	156	memcpy(pkt->data, buf, pkt_len);
	157	buf += pkt_len;
	158	len -= pkt_len;
	159	num_pkts--;
	160
	161	if (num_pkts > 0) {
	162	if (len > data->split_buf_size \|\| !data->split_buf) {
	163	av_freep(&data->split_buf);
	164	data->split_buf_size = 2 * len;
	165	data->split_buf = av_malloc(data->split_buf_size);
	166	if (!data->split_buf) {
	167	av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
	168	av_free_packet(pkt);
	169	return AVERROR(ENOMEM);
	170	}
	171	}
	172	memcpy(data->split_buf, buf, len);
	173	data->split_buf_len = len;
	174	data->split_pos = 0;
	175	data->split_pkts = num_pkts;
	176	return 1;
	177	}
	178
	179	return 0;
	180
	181	} else if (fragmented == 1) {
	182	// start of xiph data fragment
	183	int res;
	184
	185	// end packet has been lost somewhere, so drop buffered data
	186	free_fragment_if_needed(data);
	187
	188	if((res = avio_open_dyn_buf(&data->fragment)) < 0)
	189	return res;
	190
	191	avio_write(data->fragment, buf, pkt_len);
	192	data->timestamp = *timestamp;
	193
	194	} else {
	195	av_assert1(fragmented < 4);
	196	if (data->timestamp != *timestamp) {
	197	// skip if fragmented timestamp is incorrect;
	198	// a start packet has been lost somewhere
	199	free_fragment_if_needed(data);
	200	av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match!\n");
	201	return AVERROR_INVALIDDATA;
	202	}
	203	if (!data->fragment) {
	204	av_log(ctx, AV_LOG_WARNING,
	205	"Received packet without a start fragment; dropping.\n");
	206	return AVERROR(EAGAIN);
	207	}
	208
	209	// copy data to fragment buffer
	210	avio_write(data->fragment, buf, pkt_len);
	211
	212	if (fragmented == 3) {
	213	// end of xiph data packet
	214	int ret = ff_rtp_finalize_packet(pkt, &data->fragment, st->index);
	215	if (ret < 0) {
	216	av_log(ctx, AV_LOG_ERROR,
	217	"Error occurred when getting fragment buffer.");
	218	return ret;
	219	}
	220
	221	return 0;
	222	}
	223	}
	224
	225	return AVERROR(EAGAIN);
	226	}
	227
	228	/**
	229	* Length encoding described in RFC5215 section 3.1.1.
	230	*/
	231	static int get_base128(const uint8_t ** buf, const uint8_t * buf_end)
	232	{
	233	int n = 0;
	234	for (; buf < buf_end; ++buf) {
	235	n <<= 7;
	236	n += **buf & 0x7f;
	237	if (!(**buf & 0x80)) {
	238	++*buf;
	239	return n;
	240	}
	241	}
	242	return 0;
	243	}
	244
	245	/**
	246	* Based off parse_packed_headers in Vorbis RTP
	247	*/
	248	static int
	249	parse_packed_headers(const uint8_t * packed_headers,
	250	const uint8_t * packed_headers_end,
	251	AVCodecContext * codec, PayloadContext * xiph_data)
	252	{
	253
	254	unsigned num_packed, num_headers, length, length1, length2, extradata_alloc;
	255	uint8_t *ptr;
	256
	257	if (packed_headers_end - packed_headers < 9) {
	258	av_log(codec, AV_LOG_ERROR,
	259	"Invalid %"PTRDIFF_SPECIFIER" byte packed header.",
	260	packed_headers_end - packed_headers);
	261	return AVERROR_INVALIDDATA;
	262	}
	263
	264	num_packed = bytestream_get_be32(&packed_headers);
	265	xiph_data->ident = bytestream_get_be24(&packed_headers);
	266	length = bytestream_get_be16(&packed_headers);
	267	num_headers = get_base128(&packed_headers, packed_headers_end);
	268	length1 = get_base128(&packed_headers, packed_headers_end);
	269	length2 = get_base128(&packed_headers, packed_headers_end);
	270
	271	if (num_packed != 1 \|\| num_headers > 3) {
	272	av_log(codec, AV_LOG_ERROR,
	273	"Unimplemented number of headers: %d packed headers, %d headers\n",
	274	num_packed, num_headers);
	275	return AVERROR_PATCHWELCOME;
	276	}
	277
	278	if (packed_headers_end - packed_headers != length \|\|
	279	length1 > length \|\| length2 > length - length1) {
	280	av_log(codec, AV_LOG_ERROR,
	281	"Bad packed header lengths (%d,%d,%"PTRDIFF_SPECIFIER",%d)\n", length1,
	282	length2, packed_headers_end - packed_headers, length);
	283	return AVERROR_INVALIDDATA;
	284	}
	285
	286	/* allocate extra space:
	287	* -- length/255 +2 for xiphlacing
	288	* -- one for the '2' marker
	289	* -- FF_INPUT_BUFFER_PADDING_SIZE required */
	290	extradata_alloc = length + length/255 + 3 + FF_INPUT_BUFFER_PADDING_SIZE;
	291
	292	if (ff_alloc_extradata(codec, extradata_alloc)) {
	293	av_log(codec, AV_LOG_ERROR, "Out of memory\n");
	294	return AVERROR(ENOMEM);
	295	}
	296	ptr = codec->extradata;
	297	*ptr++ = 2;
	298	ptr += av_xiphlacing(ptr, length1);
	299	ptr += av_xiphlacing(ptr, length2);
	300	memcpy(ptr, packed_headers, length);
	301	ptr += length;
	302	codec->extradata_size = ptr - codec->extradata;
	303	// clear out remaining parts of the buffer
	304	memset(ptr, 0, extradata_alloc - codec->extradata_size);
	305
	306	return 0;
	307	}
	308
	309	static int xiph_parse_fmtp_pair(AVFormatContext *s,
	310	AVStream* stream,
	311	PayloadContext *xiph_data,
	312	char attr, char value)
	313	{
	314	AVCodecContext *codec = stream->codec;
	315	int result = 0;
	316
	317	if (!strcmp(attr, "sampling")) {
	318	if (!strcmp(value, "YCbCr-4:2:0")) {
	319	codec->pix_fmt = AV_PIX_FMT_YUV420P;
	320	} else if (!strcmp(value, "YCbCr-4:4:2")) {
	321	codec->pix_fmt = AV_PIX_FMT_YUV422P;
	322	} else if (!strcmp(value, "YCbCr-4:4:4")) {
	323	codec->pix_fmt = AV_PIX_FMT_YUV444P;
	324	} else {
	325	av_log(s, AV_LOG_ERROR,
	326	"Unsupported pixel format %s\n", attr);
	327	return AVERROR_INVALIDDATA;
	328	}
	329	} else if (!strcmp(attr, "width")) {
	330	/* This is an integer between 1 and 1048561
	331	* and MUST be in multiples of 16. */
	332	codec->width = atoi(value);
	333	return 0;
	334	} else if (!strcmp(attr, "height")) {
	335	/* This is an integer between 1 and 1048561
	336	* and MUST be in multiples of 16. */
	337	codec->height = atoi(value);
	338	return 0;
	339	} else if (!strcmp(attr, "delivery-method")) {
	340	/* Possible values are: inline, in_band, out_band/specific_name. */
	341	return AVERROR_PATCHWELCOME;
	342	} else if (!strcmp(attr, "configuration-uri")) {
	343	/* NOTE: configuration-uri is supported only under 2 conditions:
	344	*--after the delivery-method tag
	345	* --with a delivery-method value of out_band */
	346	return AVERROR_PATCHWELCOME;
	347	} else if (!strcmp(attr, "configuration")) {
	348	/* NOTE: configuration is supported only AFTER the delivery-method tag
	349	* The configuration value is a base64 encoded packed header */
	350	uint8_t *decoded_packet = NULL;
	351	int packet_size;
	352	size_t decoded_alloc = strlen(value) / 4 * 3 + 4;
	353
	354	if (decoded_alloc <= INT_MAX) {
	355	decoded_packet = av_malloc(decoded_alloc);
	356	if (decoded_packet) {
	357	packet_size =
	358	av_base64_decode(decoded_packet, value, decoded_alloc);
	359
	360	result = parse_packed_headers
	361	(decoded_packet, decoded_packet + packet_size, codec,
	362	xiph_data);
	363	} else {
	364	av_log(s, AV_LOG_ERROR,
	365	"Out of memory while decoding SDP configuration.\n");
	366	result = AVERROR(ENOMEM);
	367	}
	368	} else {
	369	av_log(s, AV_LOG_ERROR, "Packet too large\n");
	370	result = AVERROR_INVALIDDATA;
	371	}
	372	av_free(decoded_packet);
	373	}
	374	return result;
	375	}
	376
	377	static int xiph_parse_sdp_line(AVFormatContext *s, int st_index,
	378	PayloadContext data, const char line)
	379	{
	380	const char *p;
	381
	382	if (st_index < 0)
	383	return 0;
	384
	385	if (av_strstart(line, "fmtp:", &p)) {
	386	return ff_parse_fmtp(s, s->streams[st_index], data, p,
	387	xiph_parse_fmtp_pair);
	388	}
	389
	390	return 0;
	391	}
	392
	393	RTPDynamicProtocolHandler ff_theora_dynamic_handler = {
	394	.enc_name = "theora",
	395	.codec_type = AVMEDIA_TYPE_VIDEO,
	396	.codec_id = AV_CODEC_ID_THEORA,
	397	.parse_sdp_a_line = xiph_parse_sdp_line,
	398	.alloc = xiph_new_context,
	399	.free = xiph_free_context,
	400	.parse_packet = xiph_handle_packet
	401	};
	402
	403	RTPDynamicProtocolHandler ff_vorbis_dynamic_handler = {
	404	.enc_name = "vorbis",
	405	.codec_type = AVMEDIA_TYPE_AUDIO,
	406	.codec_id = AV_CODEC_ID_VORBIS,
	407	.init = xiph_vorbis_init,
	408	.parse_sdp_a_line = xiph_parse_sdp_line,
	409	.alloc = xiph_new_context,
	410	.free = xiph_free_context,
	411	.parse_packet = xiph_handle_packet
	412	};