diff options
Diffstat (limited to 'ffmpeg1/libavformat/rtpdec_amr.c')
| -rw-r--r-- | ffmpeg1/libavformat/rtpdec_amr.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/ffmpeg1/libavformat/rtpdec_amr.c b/ffmpeg1/libavformat/rtpdec_amr.c new file mode 100644 index 0000000..211cf17 --- /dev/null +++ b/ffmpeg1/libavformat/rtpdec_amr.c @@ -0,0 +1,209 @@ +/* + * 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 PayloadContext *amr_new_context(void) +{ + PayloadContext *data = av_mallocz(sizeof(PayloadContext)); + if(!data) return data; + data->channels = 1; + return data; +} + +static void amr_free_context(PayloadContext *data) +{ + av_free(data); +} + +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; + const uint8_t *speech_data; + uint8_t *ptr; + + if (st->codec->codec_id == AV_CODEC_ID_AMR_NB) { + frame_sizes = frame_sizes_nb; + } else if (st->codec->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->codec->channels != 1) { + av_log(ctx, AV_LOG_ERROR, "Only mono AMR is supported\n"); + return AVERROR_INVALIDDATA; + } + st->codec->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 (av_new_packet(pkt, len - 1)) { + av_log(ctx, AV_LOG_ERROR, "Out of memory\n"); + return AVERROR(ENOMEM); + } + 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(AVStream *stream, PayloadContext *data, + char *attr, 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(NULL, AV_LOG_WARNING, "AMR fmtp attribute %s had " + "nonstandard empty value\n", attr); + strcpy(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->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; +} + +RTPDynamicProtocolHandler ff_amr_nb_dynamic_handler = { + .enc_name = "AMR", + .codec_type = AVMEDIA_TYPE_AUDIO, + .codec_id = AV_CODEC_ID_AMR_NB, + .parse_sdp_a_line = amr_parse_sdp_line, + .alloc = amr_new_context, + .free = amr_free_context, + .parse_packet = amr_handle_packet, +}; + +RTPDynamicProtocolHandler ff_amr_wb_dynamic_handler = { + .enc_name = "AMR-WB", + .codec_type = AVMEDIA_TYPE_AUDIO, + .codec_id = AV_CODEC_ID_AMR_WB, + .parse_sdp_a_line = amr_parse_sdp_line, + .alloc = amr_new_context, + .free = amr_free_context, + .parse_packet = amr_handle_packet, +}; |