yading@11: /*
yading@11:  * Xiph RTP Protocols
yading@11:  * Copyright (c) 2009 Colin McQuillian
yading@11:  * Copyright (c) 2010 Josh Allmann
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: /**
yading@11:  * @file
yading@11:  * @brief Xiph / RTP Code
yading@11:  * @author Colin McQuillan <m.niloc@gmail.com>
yading@11:  * @author Josh Allmann <joshua.allmann@gmail.com>
yading@11:  */
yading@11: 
yading@11: #include "libavutil/avassert.h"
yading@11: #include "libavutil/avstring.h"
yading@11: #include "libavutil/base64.h"
yading@11: #include "libavcodec/bytestream.h"
yading@11: 
yading@11: #include "rtpdec.h"
yading@11: #include "rtpdec_formats.h"
yading@11: 
yading@11: /**
yading@11:  * RTP/Xiph specific private data.
yading@11:  */
yading@11: struct PayloadContext {
yading@11:     unsigned ident;             ///< 24-bit stream configuration identifier
yading@11:     uint32_t timestamp;
yading@11:     AVIOContext* fragment;    ///< buffer for split payloads
yading@11:     uint8_t *split_buf;
yading@11:     int split_pos, split_buf_len, split_buf_size;
yading@11:     int split_pkts;
yading@11: };
yading@11: 
yading@11: static PayloadContext *xiph_new_context(void)
yading@11: {
yading@11:     return av_mallocz(sizeof(PayloadContext));
yading@11: }
yading@11: 
yading@11: static inline void free_fragment_if_needed(PayloadContext * data)
yading@11: {
yading@11:     if (data->fragment) {
yading@11:         uint8_t* p;
yading@11:         avio_close_dyn_buf(data->fragment, &p);
yading@11:         av_free(p);
yading@11:         data->fragment = NULL;
yading@11:     }
yading@11: }
yading@11: 
yading@11: static void xiph_free_context(PayloadContext * data)
yading@11: {
yading@11:     free_fragment_if_needed(data);
yading@11:     av_free(data->split_buf);
yading@11:     av_free(data);
yading@11: }
yading@11: 
yading@11: static int xiph_vorbis_init(AVFormatContext *ctx, int st_index,
yading@11:                             PayloadContext *data)
yading@11: {
yading@11:     if (st_index < 0)
yading@11:         return 0;
yading@11:     ctx->streams[st_index]->need_parsing = AVSTREAM_PARSE_HEADERS;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: 
yading@11: static int xiph_handle_packet(AVFormatContext *ctx, PayloadContext *data,
yading@11:                               AVStream *st, AVPacket *pkt, uint32_t *timestamp,
yading@11:                               const uint8_t *buf, int len, uint16_t seq,
yading@11:                               int flags)
yading@11: {
yading@11: 
yading@11:     int ident, fragmented, tdt, num_pkts, pkt_len;
yading@11: 
yading@11:     if (!buf) {
yading@11:         if (!data->split_buf || data->split_pos + 2 > data->split_buf_len ||
yading@11:             data->split_pkts <= 0) {
yading@11:             av_log(ctx, AV_LOG_ERROR, "No more data to return\n");
yading@11:             return AVERROR_INVALIDDATA;
yading@11:         }
yading@11:         pkt_len = AV_RB16(data->split_buf + data->split_pos);
yading@11:         data->split_pos += 2;
yading@11:         if (data->split_pos + pkt_len > data->split_buf_len) {
yading@11:             av_log(ctx, AV_LOG_ERROR, "Not enough data to return\n");
yading@11:             return AVERROR_INVALIDDATA;
yading@11:         }
yading@11:         if (av_new_packet(pkt, pkt_len)) {
yading@11:             av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
yading@11:             return AVERROR(ENOMEM);
yading@11:         }
yading@11:         pkt->stream_index = st->index;
yading@11:         memcpy(pkt->data, data->split_buf + data->split_pos, pkt_len);
yading@11:         data->split_pos += pkt_len;
yading@11:         data->split_pkts--;
yading@11:         return data->split_pkts > 0;
yading@11:     }
yading@11: 
yading@11:     if (len < 6) {
yading@11:         av_log(ctx, AV_LOG_ERROR, "Invalid %d byte packet\n", len);
yading@11:         return AVERROR_INVALIDDATA;
yading@11:     }
yading@11: 
yading@11:     // read xiph rtp headers
yading@11:     ident       = AV_RB24(buf);
yading@11:     fragmented  = buf[3] >> 6;
yading@11:     tdt         = (buf[3] >> 4) & 3;
yading@11:     num_pkts    = buf[3] & 0xf;
yading@11:     pkt_len     = AV_RB16(buf + 4);
yading@11: 
yading@11:     if (pkt_len > len - 6) {
yading@11:         av_log(ctx, AV_LOG_ERROR,
yading@11:                "Invalid packet length %d in %d byte packet\n", pkt_len,
yading@11:                len);
yading@11:         return AVERROR_INVALIDDATA;
yading@11:     }
yading@11: 
yading@11:     if (ident != data->ident) {
yading@11:         av_log(ctx, AV_LOG_ERROR,
yading@11:                "Unimplemented Xiph SDP configuration change detected\n");
yading@11:         return AVERROR_PATCHWELCOME;
yading@11:     }
yading@11: 
yading@11:     if (tdt) {
yading@11:         av_log(ctx, AV_LOG_ERROR,
yading@11:                "Unimplemented RTP Xiph packet settings (%d,%d,%d)\n",
yading@11:                fragmented, tdt, num_pkts);
yading@11:         return AVERROR_PATCHWELCOME;
yading@11:     }
yading@11: 
yading@11:     buf += 6; // move past header bits
yading@11:     len -= 6;
yading@11: 
yading@11:     if (fragmented == 0) {
yading@11:         if (av_new_packet(pkt, pkt_len)) {
yading@11:             av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
yading@11:             return AVERROR(ENOMEM);
yading@11:         }
yading@11:         pkt->stream_index = st->index;
yading@11:         memcpy(pkt->data, buf, pkt_len);
yading@11:         buf += pkt_len;
yading@11:         len -= pkt_len;
yading@11:         num_pkts--;
yading@11: 
yading@11:         if (num_pkts > 0) {
yading@11:             if (len > data->split_buf_size || !data->split_buf) {
yading@11:                 av_freep(&data->split_buf);
yading@11:                 data->split_buf_size = 2 * len;
yading@11:                 data->split_buf = av_malloc(data->split_buf_size);
yading@11:                 if (!data->split_buf) {
yading@11:                     av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
yading@11:                     av_free_packet(pkt);
yading@11:                     return AVERROR(ENOMEM);
yading@11:                 }
yading@11:             }
yading@11:             memcpy(data->split_buf, buf, len);
yading@11:             data->split_buf_len = len;
yading@11:             data->split_pos = 0;
yading@11:             data->split_pkts = num_pkts;
yading@11:             return 1;
yading@11:         }
yading@11: 
yading@11:         return 0;
yading@11: 
yading@11:     } else if (fragmented == 1) {
yading@11:         // start of xiph data fragment
yading@11:         int res;
yading@11: 
yading@11:         // end packet has been lost somewhere, so drop buffered data
yading@11:         free_fragment_if_needed(data);
yading@11: 
yading@11:         if((res = avio_open_dyn_buf(&data->fragment)) < 0)
yading@11:             return res;
yading@11: 
yading@11:         avio_write(data->fragment, buf, pkt_len);
yading@11:         data->timestamp = *timestamp;
yading@11: 
yading@11:     } else {
yading@11:         av_assert1(fragmented < 4);
yading@11:         if (data->timestamp != *timestamp) {
yading@11:             // skip if fragmented timestamp is incorrect;
yading@11:             // a start packet has been lost somewhere
yading@11:             free_fragment_if_needed(data);
yading@11:             av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match!\n");
yading@11:             return AVERROR_INVALIDDATA;
yading@11:         }
yading@11:         if (!data->fragment) {
yading@11:             av_log(ctx, AV_LOG_WARNING,
yading@11:                    "Received packet without a start fragment; dropping.\n");
yading@11:             return AVERROR(EAGAIN);
yading@11:         }
yading@11: 
yading@11:         // copy data to fragment buffer
yading@11:         avio_write(data->fragment, buf, pkt_len);
yading@11: 
yading@11:         if (fragmented == 3) {
yading@11:             // end of xiph data packet
yading@11:             int ret = ff_rtp_finalize_packet(pkt, &data->fragment, st->index);
yading@11:             if (ret < 0) {
yading@11:                 av_log(ctx, AV_LOG_ERROR,
yading@11:                        "Error occurred when getting fragment buffer.");
yading@11:                 return ret;
yading@11:             }
yading@11: 
yading@11:             return 0;
yading@11:         }
yading@11:     }
yading@11: 
yading@11:    return AVERROR(EAGAIN);
yading@11: }
yading@11: 
yading@11: /**
yading@11:  * Length encoding described in RFC5215 section 3.1.1.
yading@11:  */
yading@11: static int get_base128(const uint8_t ** buf, const uint8_t * buf_end)
yading@11: {
yading@11:     int n = 0;
yading@11:     for (; *buf < buf_end; ++*buf) {
yading@11:         n <<= 7;
yading@11:         n += **buf & 0x7f;
yading@11:         if (!(**buf & 0x80)) {
yading@11:             ++*buf;
yading@11:             return n;
yading@11:         }
yading@11:     }
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: /**
yading@11:  * Based off parse_packed_headers in Vorbis RTP
yading@11:  */
yading@11: static int
yading@11: parse_packed_headers(const uint8_t * packed_headers,
yading@11:                      const uint8_t * packed_headers_end,
yading@11:                      AVCodecContext * codec, PayloadContext * xiph_data)
yading@11: {
yading@11: 
yading@11:     unsigned num_packed, num_headers, length, length1, length2, extradata_alloc;
yading@11:     uint8_t *ptr;
yading@11: 
yading@11:     if (packed_headers_end - packed_headers < 9) {
yading@11:         av_log(codec, AV_LOG_ERROR,
yading@11:                "Invalid %td byte packed header.",
yading@11:                packed_headers_end - packed_headers);
yading@11:         return AVERROR_INVALIDDATA;
yading@11:     }
yading@11: 
yading@11:     num_packed         = bytestream_get_be32(&packed_headers);
yading@11:     xiph_data->ident   = bytestream_get_be24(&packed_headers);
yading@11:     length             = bytestream_get_be16(&packed_headers);
yading@11:     num_headers        = get_base128(&packed_headers, packed_headers_end);
yading@11:     length1            = get_base128(&packed_headers, packed_headers_end);
yading@11:     length2            = get_base128(&packed_headers, packed_headers_end);
yading@11: 
yading@11:     if (num_packed != 1 || num_headers > 3) {
yading@11:         av_log(codec, AV_LOG_ERROR,
yading@11:                "Unimplemented number of headers: %d packed headers, %d headers\n",
yading@11:                num_packed, num_headers);
yading@11:         return AVERROR_PATCHWELCOME;
yading@11:     }
yading@11: 
yading@11:     if (packed_headers_end - packed_headers != length ||
yading@11:         length1 > length || length2 > length - length1) {
yading@11:         av_log(codec, AV_LOG_ERROR,
yading@11:                "Bad packed header lengths (%d,%d,%td,%d)\n", length1,
yading@11:                length2, packed_headers_end - packed_headers, length);
yading@11:         return AVERROR_INVALIDDATA;
yading@11:     }
yading@11: 
yading@11:     /* allocate extra space:
yading@11:      * -- length/255 +2 for xiphlacing
yading@11:      * -- one for the '2' marker
yading@11:      * -- FF_INPUT_BUFFER_PADDING_SIZE required */
yading@11:     extradata_alloc = length + length/255 + 3 + FF_INPUT_BUFFER_PADDING_SIZE;
yading@11: 
yading@11:     ptr = codec->extradata = av_malloc(extradata_alloc);
yading@11:     if (!ptr) {
yading@11:         av_log(codec, AV_LOG_ERROR, "Out of memory\n");
yading@11:         return AVERROR(ENOMEM);
yading@11:     }
yading@11:     *ptr++ = 2;
yading@11:     ptr += av_xiphlacing(ptr, length1);
yading@11:     ptr += av_xiphlacing(ptr, length2);
yading@11:     memcpy(ptr, packed_headers, length);
yading@11:     ptr += length;
yading@11:     codec->extradata_size = ptr - codec->extradata;
yading@11:     // clear out remaining parts of the buffer
yading@11:     memset(ptr, 0, extradata_alloc - codec->extradata_size);
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int xiph_parse_fmtp_pair(AVStream* stream,
yading@11:                                 PayloadContext *xiph_data,
yading@11:                                 char *attr, char *value)
yading@11: {
yading@11:     AVCodecContext *codec = stream->codec;
yading@11:     int result = 0;
yading@11: 
yading@11:     if (!strcmp(attr, "sampling")) {
yading@11:         if (!strcmp(value, "YCbCr-4:2:0")) {
yading@11:             codec->pix_fmt = AV_PIX_FMT_YUV420P;
yading@11:         } else if (!strcmp(value, "YCbCr-4:4:2")) {
yading@11:             codec->pix_fmt = AV_PIX_FMT_YUV422P;
yading@11:         } else if (!strcmp(value, "YCbCr-4:4:4")) {
yading@11:             codec->pix_fmt = AV_PIX_FMT_YUV444P;
yading@11:         } else {
yading@11:             av_log(codec, AV_LOG_ERROR,
yading@11:                    "Unsupported pixel format %s\n", attr);
yading@11:             return AVERROR_INVALIDDATA;
yading@11:         }
yading@11:     } else if (!strcmp(attr, "width")) {
yading@11:         /* This is an integer between 1 and 1048561
yading@11:          * and MUST be in multiples of 16. */
yading@11:         codec->width = atoi(value);
yading@11:         return 0;
yading@11:     } else if (!strcmp(attr, "height")) {
yading@11:         /* This is an integer between 1 and 1048561
yading@11:          * and MUST be in multiples of 16. */
yading@11:         codec->height = atoi(value);
yading@11:         return 0;
yading@11:     } else if (!strcmp(attr, "delivery-method")) {
yading@11:         /* Possible values are: inline, in_band, out_band/specific_name. */
yading@11:         return AVERROR_PATCHWELCOME;
yading@11:     } else if (!strcmp(attr, "configuration-uri")) {
yading@11:         /* NOTE: configuration-uri is supported only under 2 conditions:
yading@11:          *--after the delivery-method tag
yading@11:          * --with a delivery-method value of out_band */
yading@11:         return AVERROR_PATCHWELCOME;
yading@11:     } else if (!strcmp(attr, "configuration")) {
yading@11:         /* NOTE: configuration is supported only AFTER the delivery-method tag
yading@11:          * The configuration value is a base64 encoded packed header */
yading@11:         uint8_t *decoded_packet = NULL;
yading@11:         int packet_size;
yading@11:         size_t decoded_alloc = strlen(value) / 4 * 3 + 4;
yading@11: 
yading@11:         if (decoded_alloc <= INT_MAX) {
yading@11:             decoded_packet = av_malloc(decoded_alloc);
yading@11:             if (decoded_packet) {
yading@11:                 packet_size =
yading@11:                     av_base64_decode(decoded_packet, value, decoded_alloc);
yading@11: 
yading@11:                 result = parse_packed_headers
yading@11:                     (decoded_packet, decoded_packet + packet_size, codec,
yading@11:                     xiph_data);
yading@11:             } else {
yading@11:                 av_log(codec, AV_LOG_ERROR,
yading@11:                        "Out of memory while decoding SDP configuration.\n");
yading@11:                 result = AVERROR(ENOMEM);
yading@11:             }
yading@11:         } else {
yading@11:             av_log(codec, AV_LOG_ERROR, "Packet too large\n");
yading@11:             result = AVERROR_INVALIDDATA;
yading@11:         }
yading@11:         av_free(decoded_packet);
yading@11:     }
yading@11:     return result;
yading@11: }
yading@11: 
yading@11: static int xiph_parse_sdp_line(AVFormatContext *s, int st_index,
yading@11:                                PayloadContext *data, const char *line)
yading@11: {
yading@11:     const char *p;
yading@11: 
yading@11:     if (st_index < 0)
yading@11:         return 0;
yading@11: 
yading@11:     if (av_strstart(line, "fmtp:", &p)) {
yading@11:         return ff_parse_fmtp(s->streams[st_index], data, p,
yading@11:                              xiph_parse_fmtp_pair);
yading@11:     }
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: RTPDynamicProtocolHandler ff_theora_dynamic_handler = {
yading@11:     .enc_name         = "theora",
yading@11:     .codec_type       = AVMEDIA_TYPE_VIDEO,
yading@11:     .codec_id         = AV_CODEC_ID_THEORA,
yading@11:     .parse_sdp_a_line = xiph_parse_sdp_line,
yading@11:     .alloc            = xiph_new_context,
yading@11:     .free             = xiph_free_context,
yading@11:     .parse_packet     = xiph_handle_packet
yading@11: };
yading@11: 
yading@11: RTPDynamicProtocolHandler ff_vorbis_dynamic_handler = {
yading@11:     .enc_name         = "vorbis",
yading@11:     .codec_type       = AVMEDIA_TYPE_AUDIO,
yading@11:     .codec_id         = AV_CODEC_ID_VORBIS,
yading@11:     .init             = xiph_vorbis_init,
yading@11:     .parse_sdp_a_line = xiph_parse_sdp_line,
yading@11:     .alloc            = xiph_new_context,
yading@11:     .free             = xiph_free_context,
yading@11:     .parse_packet     = xiph_handle_packet
yading@11: };