| /* |
| * RTP AMR Depacketizer, RFC 3267 |
| * Copyright (c) 2010 Martin Storsjo |
| * |
| * 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 |
| */ |
| |
| #include "libavutil/channel_layout.h" |
| #include "avformat.h" |
| #include "rtpdec_formats.h" |
| #include "libavutil/avstring.h" |
| |
| static const uint8_t frame_sizes_nb[16] = { |
| 12, 13, 15, 17, 19, 20, 26, 31, 5, 0, 0, 0, 0, 0, 0, 0 |
| }; |
| static const uint8_t frame_sizes_wb[16] = { |
| 17, 23, 32, 36, 40, 46, 50, 58, 60, 5, 5, 0, 0, 0, 0, 0 |
| }; |
| |
| struct PayloadContext { |
| int octet_align; |
| int crc; |
| int interleaving; |
| int channels; |
| }; |
| |
| static av_cold int amr_init(AVFormatContext *s, int st_index, PayloadContext *data) |
| { |
| data->channels = 1; |
| return 0; |
| } |
| |
| static int amr_handle_packet(AVFormatContext *ctx, PayloadContext *data, |
| AVStream *st, AVPacket *pkt, uint32_t *timestamp, |
| const uint8_t *buf, int len, uint16_t seq, |
| int flags) |
| { |
| const uint8_t *frame_sizes = NULL; |
| int frames; |
| int i, ret; |
| const uint8_t *speech_data; |
| uint8_t *ptr; |
| |
| if (st->codecpar->codec_id == AV_CODEC_ID_AMR_NB) { |
| frame_sizes = frame_sizes_nb; |
| } else if (st->codecpar->codec_id == AV_CODEC_ID_AMR_WB) { |
| frame_sizes = frame_sizes_wb; |
| } else { |
| av_log(ctx, AV_LOG_ERROR, "Bad codec ID\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| if (st->codecpar->channels != 1) { |
| av_log(ctx, AV_LOG_ERROR, "Only mono AMR is supported\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| st->codecpar->channel_layout = AV_CH_LAYOUT_MONO; |
| |
| /* The AMR RTP packet consists of one header byte, followed |
| * by one TOC byte for each AMR frame in the packet, followed |
| * by the speech data for all the AMR frames. |
| * |
| * The header byte contains only a codec mode request, for |
| * requesting what kind of AMR data the sender wants to |
| * receive. Not used at the moment. |
| */ |
| |
| /* Count the number of frames in the packet. The highest bit |
| * is set in a TOC byte if there are more frames following. |
| */ |
| for (frames = 1; frames < len && (buf[frames] & 0x80); frames++) ; |
| |
| if (1 + frames >= len) { |
| /* We hit the end of the packet while counting frames. */ |
| av_log(ctx, AV_LOG_ERROR, "No speech data found\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| speech_data = buf + 1 + frames; |
| |
| /* Everything except the codec mode request byte should be output. */ |
| if ((ret = av_new_packet(pkt, len - 1)) < 0) { |
| av_log(ctx, AV_LOG_ERROR, "Out of memory\n"); |
| return ret; |
| } |
| pkt->stream_index = st->index; |
| ptr = pkt->data; |
| |
| for (i = 0; i < frames; i++) { |
| uint8_t toc = buf[1 + i]; |
| int frame_size = frame_sizes[(toc >> 3) & 0x0f]; |
| |
| if (speech_data + frame_size > buf + len) { |
| /* Too little speech data */ |
| av_log(ctx, AV_LOG_WARNING, "Too little speech data in the RTP packet\n"); |
| /* Set the unwritten part of the packet to zero. */ |
| memset(ptr, 0, pkt->data + pkt->size - ptr); |
| pkt->size = ptr - pkt->data; |
| return 0; |
| } |
| |
| /* Extract the AMR frame mode from the TOC byte */ |
| *ptr++ = toc & 0x7C; |
| |
| /* Copy the speech data */ |
| memcpy(ptr, speech_data, frame_size); |
| speech_data += frame_size; |
| ptr += frame_size; |
| } |
| |
| if (speech_data < buf + len) { |
| av_log(ctx, AV_LOG_WARNING, "Too much speech data in the RTP packet?\n"); |
| /* Set the unwritten part of the packet to zero. */ |
| memset(ptr, 0, pkt->data + pkt->size - ptr); |
| pkt->size = ptr - pkt->data; |
| } |
| |
| return 0; |
| } |
| |
| static int amr_parse_fmtp(AVFormatContext *s, |
| AVStream *stream, PayloadContext *data, |
| const char *attr, const char *value) |
| { |
| /* Some AMR SDP configurations contain "octet-align", without |
| * the trailing =1. Therefore, if the value is empty, |
| * interpret it as "1". |
| */ |
| if (!strcmp(value, "")) { |
| av_log(s, AV_LOG_WARNING, "AMR fmtp attribute %s had " |
| "nonstandard empty value\n", attr); |
| value = "1"; |
| } |
| if (!strcmp(attr, "octet-align")) |
| data->octet_align = atoi(value); |
| else if (!strcmp(attr, "crc")) |
| data->crc = atoi(value); |
| else if (!strcmp(attr, "interleaving")) |
| data->interleaving = atoi(value); |
| else if (!strcmp(attr, "channels")) |
| data->channels = atoi(value); |
| return 0; |
| } |
| |
| static int amr_parse_sdp_line(AVFormatContext *s, int st_index, |
| PayloadContext *data, const char *line) |
| { |
| const char *p; |
| int ret; |
| |
| if (st_index < 0) |
| return 0; |
| |
| /* Parse an fmtp line this one: |
| * a=fmtp:97 octet-align=1; interleaving=0 |
| * That is, a normal fmtp: line followed by semicolon & space |
| * separated key/value pairs. |
| */ |
| if (av_strstart(line, "fmtp:", &p)) { |
| ret = ff_parse_fmtp(s, s->streams[st_index], data, p, amr_parse_fmtp); |
| if (!data->octet_align || data->crc || |
| data->interleaving || data->channels != 1) { |
| av_log(s, AV_LOG_ERROR, "Unsupported RTP/AMR configuration!\n"); |
| return -1; |
| } |
| return ret; |
| } |
| return 0; |
| } |
| |
| const RTPDynamicProtocolHandler ff_amr_nb_dynamic_handler = { |
| .enc_name = "AMR", |
| .codec_type = AVMEDIA_TYPE_AUDIO, |
| .codec_id = AV_CODEC_ID_AMR_NB, |
| .priv_data_size = sizeof(PayloadContext), |
| .init = amr_init, |
| .parse_sdp_a_line = amr_parse_sdp_line, |
| .parse_packet = amr_handle_packet, |
| }; |
| |
| const RTPDynamicProtocolHandler ff_amr_wb_dynamic_handler = { |
| .enc_name = "AMR-WB", |
| .codec_type = AVMEDIA_TYPE_AUDIO, |
| .codec_id = AV_CODEC_ID_AMR_WB, |
| .priv_data_size = sizeof(PayloadContext), |
| .init = amr_init, |
| .parse_sdp_a_line = amr_parse_sdp_line, |
| .parse_packet = amr_handle_packet, |
| }; |