/* * RTP H264 Protocol (RFC3984) * Copyright (c) 2006 Ryan Martell * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * @brief H.264 / RTP Code (RFC3984) * @author Ryan Martell <rdm4@martellventures.com> * * @note Notes: * Notes: * This currently supports packetization mode: * Single Nal Unit Mode (0), or * Non-Interleaved Mode (1). It currently does not support * Interleaved Mode (2). (This requires implementing STAP-B, MTAP16, MTAP24, * FU-B packet types) */ #include "libavutil/attributes.h" #include "libavutil/base64.h" #include "libavutil/avstring.h" #include "libavcodec/get_bits.h" #include "avformat.h" #include "network.h" #include <assert.h> #include "rtpdec.h" #include "rtpdec_formats.h" struct PayloadContext { // sdp setup parameters uint8_t profile_idc; uint8_t profile_iop; uint8_t level_idc; int packetization_mode; #ifdef DEBUG int packet_types_received[32]; #endif }; #ifdef DEBUG #define COUNT_NAL_TYPE(data, nal) data->packet_types_received[(nal) & 0x1f]++ #else #define COUNT_NAL_TYPE(data, nal) do { } while (0) #endif static const uint8_t start_sequence[] = { 0, 0, 0, 1 }; static int sdp_parse_fmtp_config_h264(AVFormatContext *s, AVStream *stream, PayloadContext *h264_data, char *attr, char *value) { AVCodecContext *codec = stream->codec; assert(codec->codec_id == AV_CODEC_ID_H264); assert(h264_data != NULL); if (!strcmp(attr, "packetization-mode")) { av_log(s, AV_LOG_DEBUG, "RTP Packetization Mode: %d\n", atoi(value)); h264_data->packetization_mode = atoi(value); /* * Packetization Mode: * 0 or not present: Single NAL mode (Only nals from 1-23 are allowed) * 1: Non-interleaved Mode: 1-23, 24 (STAP-A), 28 (FU-A) are allowed. * 2: Interleaved Mode: 25 (STAP-B), 26 (MTAP16), 27 (MTAP24), 28 (FU-A), * and 29 (FU-B) are allowed. */ if (h264_data->packetization_mode > 1) av_log(s, AV_LOG_ERROR, "Interleaved RTP mode is not supported yet.\n"); } else if (!strcmp(attr, "profile-level-id")) { if (strlen(value) == 6) { char buffer[3]; // 6 characters=3 bytes, in hex. uint8_t profile_idc; uint8_t profile_iop; uint8_t level_idc; buffer[0] = value[0]; buffer[1] = value[1]; buffer[2] = '\0'; profile_idc = strtol(buffer, NULL, 16); buffer[0] = value[2]; buffer[1] = value[3]; profile_iop = strtol(buffer, NULL, 16); buffer[0] = value[4]; buffer[1] = value[5]; level_idc = strtol(buffer, NULL, 16); av_log(s, AV_LOG_DEBUG, "RTP Profile IDC: %x Profile IOP: %x Level: %x\n", profile_idc, profile_iop, level_idc); h264_data->profile_idc = profile_idc; h264_data->profile_iop = profile_iop; h264_data->level_idc = level_idc; } } else if (!strcmp(attr, "sprop-parameter-sets")) { codec->extradata_size = 0; av_freep(&codec->extradata); while (*value) { char base64packet[1024]; uint8_t decoded_packet[1024]; int packet_size; char *dst = base64packet; while (*value && *value != ',' && (dst - base64packet) < sizeof(base64packet) - 1) { *dst++ = *value++; } *dst++ = '\0'; if (*value == ',') value++; packet_size = av_base64_decode(decoded_packet, base64packet, sizeof(decoded_packet)); if (packet_size > 0) { uint8_t *dest = av_malloc(packet_size + sizeof(start_sequence) + codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE); if (!dest) { av_log(s, AV_LOG_ERROR, "Unable to allocate memory for extradata!\n"); return AVERROR(ENOMEM); } if (codec->extradata_size) { memcpy(dest, codec->extradata, codec->extradata_size); av_free(codec->extradata); } memcpy(dest + codec->extradata_size, start_sequence, sizeof(start_sequence)); memcpy(dest + codec->extradata_size + sizeof(start_sequence), decoded_packet, packet_size); memset(dest + codec->extradata_size + sizeof(start_sequence) + packet_size, 0, FF_INPUT_BUFFER_PADDING_SIZE); codec->extradata = dest; codec->extradata_size += sizeof(start_sequence) + packet_size; } } av_log(s, AV_LOG_DEBUG, "Extradata set to %p (size: %d)!\n", codec->extradata, codec->extradata_size); } return 0; } // return 0 on packet, no more left, 1 on packet, 1 on partial packet static int h264_handle_packet(AVFormatContext *ctx, PayloadContext *data, AVStream *st, AVPacket *pkt, uint32_t *timestamp, const uint8_t *buf, int len, uint16_t seq, int flags) { uint8_t nal; uint8_t type; int result = 0; if (!len) { av_log(ctx, AV_LOG_ERROR, "Empty H264 RTP packet\n"); return AVERROR_INVALIDDATA; } nal = buf[0]; type = nal & 0x1f; assert(data); assert(buf); /* Simplify the case (these are all the nal types used internally by * the h264 codec). */ if (type >= 1 && type <= 23) type = 1; switch (type) { case 0: // undefined, but pass them through case 1: if ((result = av_new_packet(pkt, len + sizeof(start_sequence))) < 0) return result; memcpy(pkt->data, start_sequence, sizeof(start_sequence)); memcpy(pkt->data + sizeof(start_sequence), buf, len); COUNT_NAL_TYPE(data, nal); break; case 24: // STAP-A (one packet, multiple nals) // consume the STAP-A NAL buf++; len--; // first we are going to figure out the total size { int pass = 0; int total_length = 0; uint8_t *dst = NULL; for (pass = 0; pass < 2; pass++) { const uint8_t *src = buf; int src_len = len; while (src_len > 2) { uint16_t nal_size = AV_RB16(src); // consume the length of the aggregate src += 2; src_len -= 2; if (nal_size <= src_len) { if (pass == 0) { // counting total_length += sizeof(start_sequence) + nal_size; } else { // copying assert(dst); memcpy(dst, start_sequence, sizeof(start_sequence)); dst += sizeof(start_sequence); memcpy(dst, src, nal_size); COUNT_NAL_TYPE(data, *src); dst += nal_size; } } else { av_log(ctx, AV_LOG_ERROR, "nal size exceeds length: %d %d\n", nal_size, src_len); } // eat what we handled src += nal_size; src_len -= nal_size; if (src_len < 0) av_log(ctx, AV_LOG_ERROR, "Consumed more bytes than we got! (%d)\n", src_len); } if (pass == 0) { /* now we know the total size of the packet (with the * start sequences added) */ if ((result = av_new_packet(pkt, total_length)) < 0) return result; dst = pkt->data; } else { assert(dst - pkt->data == total_length); } } } break; case 25: // STAP-B case 26: // MTAP-16 case 27: // MTAP-24 case 29: // FU-B av_log(ctx, AV_LOG_ERROR, "Unhandled type (%d) (See RFC for implementation details\n", type); result = AVERROR(ENOSYS); break; case 28: // FU-A (fragmented nal) buf++; len--; // skip the fu_indicator if (len > 1) { // these are the same as above, we just redo them here for clarity uint8_t fu_indicator = nal; uint8_t fu_header = *buf; uint8_t start_bit = fu_header >> 7; uint8_t av_unused end_bit = (fu_header & 0x40) >> 6; uint8_t nal_type = fu_header & 0x1f; uint8_t reconstructed_nal; // Reconstruct this packet's true nal; only the data follows. /* The original nal forbidden bit and NRI are stored in this * packet's nal. */ reconstructed_nal = fu_indicator & 0xe0; reconstructed_nal |= nal_type; // skip the fu_header buf++; len--; if (start_bit) COUNT_NAL_TYPE(data, nal_type); if (start_bit) { /* copy in the start sequence, and the reconstructed nal */ if ((result = av_new_packet(pkt, sizeof(start_sequence) + sizeof(nal) + len)) < 0) return result; memcpy(pkt->data, start_sequence, sizeof(start_sequence)); pkt->data[sizeof(start_sequence)] = reconstructed_nal; memcpy(pkt->data + sizeof(start_sequence) + sizeof(nal), buf, len); } else { if ((result = av_new_packet(pkt, len)) < 0) return result; memcpy(pkt->data, buf, len); } } else { av_log(ctx, AV_LOG_ERROR, "Too short data for FU-A H264 RTP packet\n"); result = AVERROR_INVALIDDATA; } break; case 30: // undefined case 31: // undefined default: av_log(ctx, AV_LOG_ERROR, "Undefined type (%d)\n", type); result = AVERROR_INVALIDDATA; break; } pkt->stream_index = st->index; return result; } static PayloadContext *h264_new_context(void) { return av_mallocz(sizeof(PayloadContext) + FF_INPUT_BUFFER_PADDING_SIZE); } static void h264_free_context(PayloadContext *data) { #ifdef DEBUG int ii; for (ii = 0; ii < 32; ii++) { if (data->packet_types_received[ii]) av_log(NULL, AV_LOG_DEBUG, "Received %d packets of type %d\n", data->packet_types_received[ii], ii); } #endif av_free(data); } static av_cold int h264_init(AVFormatContext *s, int st_index, PayloadContext *data) { if (st_index < 0) return 0; s->streams[st_index]->need_parsing = AVSTREAM_PARSE_FULL; return 0; } static int parse_h264_sdp_line(AVFormatContext *s, int st_index, PayloadContext *h264_data, const char *line) { AVStream *stream; AVCodecContext *codec; const char *p = line; if (st_index < 0) return 0; stream = s->streams[st_index]; codec = stream->codec; if (av_strstart(p, "framesize:", &p)) { char buf1[50]; char *dst = buf1; // remove the protocol identifier while (*p && *p == ' ') p++; // strip spaces. while (*p && *p != ' ') p++; // eat protocol identifier while (*p && *p == ' ') p++; // strip trailing spaces. while (*p && *p != '-' && (dst - buf1) < sizeof(buf1) - 1) *dst++ = *p++; *dst = '\0'; // a='framesize:96 320-240' // set our parameters codec->width = atoi(buf1); codec->height = atoi(p + 1); // skip the - } else if (av_strstart(p, "fmtp:", &p)) { return ff_parse_fmtp(s, stream, h264_data, p, sdp_parse_fmtp_config_h264); } else if (av_strstart(p, "cliprect:", &p)) { // could use this if we wanted. } return 0; } RTPDynamicProtocolHandler ff_h264_dynamic_handler = { .enc_name = "H264", .codec_type = AVMEDIA_TYPE_VIDEO, .codec_id = AV_CODEC_ID_H264, .init = h264_init, .parse_sdp_a_line = parse_h264_sdp_line, .alloc = h264_new_context, .free = h264_free_context, .parse_packet = h264_handle_packet };