/* * RTP Depacketization of QCELP/PureVoice, RFC 2658 * Copyright (c) 2010 Martin Storsjo * * 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 */ #include "rtpdec_formats.h" static const uint8_t frame_sizes[] = { 1, 4, 8, 17, 35 }; typedef struct InterleavePacket { int pos; int size; /* The largest frame is 35 bytes, only 10 frames are allowed per * packet, and we return the first one immediately, so allocate * space for 9 frames */ uint8_t data[35*9]; } InterleavePacket; struct PayloadContext { int interleave_size; int interleave_index; InterleavePacket group[6]; int group_finished; /* The maximum packet size, 10 frames of 35 bytes each, and one * packet header byte. */ uint8_t next_data[1 + 35*10]; int next_size; uint32_t next_timestamp; }; static int return_stored_frame(AVFormatContext *ctx, PayloadContext *data, AVStream *st, AVPacket *pkt, uint32_t *timestamp, const uint8_t *buf, int len); static int store_packet(AVFormatContext *ctx, PayloadContext *data, AVStream *st, AVPacket *pkt, uint32_t *timestamp, const uint8_t *buf, int len) { int interleave_size, interleave_index; int frame_size, ret; InterleavePacket* ip; if (len < 2) return AVERROR_INVALIDDATA; interleave_size = buf[0] >> 3 & 7; interleave_index = buf[0] & 7; if (interleave_size > 5) { av_log(ctx, AV_LOG_ERROR, "Invalid interleave size %d\n", interleave_size); return AVERROR_INVALIDDATA; } if (interleave_index > interleave_size) { av_log(ctx, AV_LOG_ERROR, "Invalid interleave index %d/%d\n", interleave_index, interleave_size); return AVERROR_INVALIDDATA; } if (interleave_size != data->interleave_size) { int i; /* First packet, or changed interleave size */ data->interleave_size = interleave_size; data->interleave_index = 0; for (i = 0; i < 6; i++) data->group[i].size = 0; } if (interleave_index < data->interleave_index) { /* Wrapped around - missed the last packet of the previous group. */ if (data->group_finished) { /* No more data in the packets in this interleaving group, just * start processing the next one */ data->interleave_index = 0; } else { /* Stash away the current packet, emit everything we have of the * previous group. */ for (; data->interleave_index <= interleave_size; data->interleave_index++) data->group[data->interleave_index].size = 0; if (len > sizeof(data->next_data)) return AVERROR_INVALIDDATA; memcpy(data->next_data, buf, len); data->next_size = len; data->next_timestamp = *timestamp; *timestamp = RTP_NOTS_VALUE; data->interleave_index = 0; return return_stored_frame(ctx, data, st, pkt, timestamp, buf, len); } } if (interleave_index > data->interleave_index) { /* We missed a packet */ for (; data->interleave_index < interleave_index; data->interleave_index++) data->group[data->interleave_index].size = 0; } data->interleave_index = interleave_index; if (buf[1] >= FF_ARRAY_ELEMS(frame_sizes)) return AVERROR_INVALIDDATA; frame_size = frame_sizes[buf[1]]; if (1 + frame_size > len) return AVERROR_INVALIDDATA; if (len - 1 - frame_size > sizeof(data->group[0].data)) return AVERROR_INVALIDDATA; if ((ret = av_new_packet(pkt, frame_size)) < 0) return ret; memcpy(pkt->data, &buf[1], frame_size); pkt->stream_index = st->index; ip = &data->group[data->interleave_index]; ip->size = len - 1 - frame_size; ip->pos = 0; memcpy(ip->data, &buf[1 + frame_size], ip->size); /* Each packet must contain the same number of frames according to the * RFC. If there's no data left in this packet, there shouldn't be any * in any of the other frames in the interleaving group either. */ data->group_finished = ip->size == 0; if (interleave_index == interleave_size) { data->interleave_index = 0; return !data->group_finished; } else { data->interleave_index++; return 0; } } static int return_stored_frame(AVFormatContext *ctx, PayloadContext *data, AVStream *st, AVPacket *pkt, uint32_t *timestamp, const uint8_t *buf, int len) { InterleavePacket* ip = &data->group[data->interleave_index]; int frame_size, ret; if (data->group_finished && data->interleave_index == 0) { *timestamp = data->next_timestamp; ret = store_packet(ctx, data, st, pkt, timestamp, data->next_data, data->next_size); data->next_size = 0; return ret; } if (ip->size == 0) { /* No stored data for this interleave block, output an empty packet */ if ((ret = av_new_packet(pkt, 1)) < 0) return ret; pkt->data[0] = 0; // Blank - could also be 14, Erasure } else { if (ip->pos >= ip->size) return AVERROR_INVALIDDATA; if (ip->data[ip->pos] >= FF_ARRAY_ELEMS(frame_sizes)) return AVERROR_INVALIDDATA; frame_size = frame_sizes[ip->data[ip->pos]]; if (ip->pos + frame_size > ip->size) return AVERROR_INVALIDDATA; if ((ret = av_new_packet(pkt, frame_size)) < 0) return ret; memcpy(pkt->data, &ip->data[ip->pos], frame_size); ip->pos += frame_size; data->group_finished = ip->pos >= ip->size; } pkt->stream_index = st->index; if (data->interleave_index == data->interleave_size) { data->interleave_index = 0; if (!data->group_finished) return 1; else return data->next_size > 0; } else { data->interleave_index++; return 1; } } static int qcelp_parse_packet(AVFormatContext *ctx, PayloadContext *data, AVStream *st, AVPacket *pkt, uint32_t *timestamp, const uint8_t *buf, int len, uint16_t seq, int flags) { if (buf) return store_packet(ctx, data, st, pkt, timestamp, buf, len); else return return_stored_frame(ctx, data, st, pkt, timestamp, buf, len); } RTPDynamicProtocolHandler ff_qcelp_dynamic_handler = { .enc_name = "x-Purevoice", .codec_type = AVMEDIA_TYPE_AUDIO, .codec_id = AV_CODEC_ID_QCELP, .priv_data_size = sizeof(PayloadContext), .static_payload_id = 12, .parse_packet = qcelp_parse_packet, };