/* * 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/avstring.h" #include "libavutil/base64.h" #include "libavcodec/bytestream.h" #include <assert.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 int xiph_handle_packet(AVFormatContext * ctx, PayloadContext * data, AVStream * st, AVPacket * pkt, uint32_t * timestamp, const uint8_t * buf, int len, 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 { assert(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 av_init_packet(pkt); pkt->size = avio_close_dyn_buf(data->fragment, &pkt->data); if (pkt->size < 0) { av_log(ctx, AV_LOG_ERROR, "Error occurred when getting fragment buffer."); return pkt->size; } pkt->stream_index = st->index; pkt->destruct = av_destruct_packet; data->fragment = NULL; 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 unsigned 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 %td 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,%td,%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; ptr = codec->extradata = av_malloc(extradata_alloc); if (!ptr) { av_log(codec, AV_LOG_ERROR, "Out of memory\n"); return AVERROR(ENOMEM); } *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(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 = PIX_FMT_YUV420P; } else if (!strcmp(value, "YCbCr-4:4:2")) { codec->pix_fmt = PIX_FMT_YUV422P; } else if (!strcmp(value, "YCbCr-4:4:4")) { codec->pix_fmt = PIX_FMT_YUV444P; } else { av_log(codec, 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(codec, AV_LOG_ERROR, "Out of memory while decoding SDP configuration.\n"); result = AVERROR(ENOMEM); } } else { av_log(codec, 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->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 = 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 = CODEC_ID_VORBIS, .parse_sdp_a_line = xiph_parse_sdp_line, .alloc = xiph_new_context, .free = xiph_free_context, .parse_packet = xiph_handle_packet };