| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | /* | ||
| 2 | * RAW GSM demuxer | ||
| 3 | * Copyright (c) 2011 Justin Ruggles | ||
| 4 | * | ||
| 5 | * This file is part of FFmpeg. | ||
| 6 | * | ||
| 7 | * FFmpeg is free software; you can redistribute it and/or | ||
| 8 | * modify it under the terms of the GNU Lesser General Public | ||
| 9 | * License as published by the Free Software Foundation; either | ||
| 10 | * version 2.1 of the License, or (at your option) any later version. | ||
| 11 | * | ||
| 12 | * FFmpeg is distributed in the hope that it will be useful, | ||
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
| 15 | * Lesser General Public License for more details. | ||
| 16 | * | ||
| 17 | * You should have received a copy of the GNU Lesser General Public | ||
| 18 | * License along with FFmpeg; if not, write to the Free Software | ||
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
| 20 | */ | ||
| 21 | |||
| 22 | #include "libavutil/channel_layout.h" | ||
| 23 | #include "libavutil/mathematics.h" | ||
| 24 | #include "libavutil/opt.h" | ||
| 25 | #include "avformat.h" | ||
| 26 | #include "demux.h" | ||
| 27 | #include "internal.h" | ||
| 28 | |||
| 29 | #define GSM_BLOCK_SIZE 33 | ||
| 30 | #define GSM_BLOCK_SAMPLES 160 | ||
| 31 | #define GSM_SAMPLE_RATE 8000 | ||
| 32 | |||
| 33 | typedef struct GSMDemuxerContext { | ||
| 34 | AVClass *class; | ||
| 35 | int sample_rate; | ||
| 36 | } GSMDemuxerContext; | ||
| 37 | |||
| 38 | 7186 | static int gsm_probe(const AVProbeData *p) | |
| 39 | { | ||
| 40 | 7186 | int valid = 0, invalid = 0; | |
| 41 | 7186 | uint8_t *b = p->buf; | |
| 42 |
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11391610 | while (b < p->buf + p->buf_size - 32) { |
| 43 |
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11384424 | if ((*b & 0xf0) == 0xd0) { |
| 44 | 1200624 | valid++; | |
| 45 | } else { | ||
| 46 | 10183800 | invalid++; | |
| 47 | } | ||
| 48 | 11384424 | b += 33; | |
| 49 | } | ||
| 50 |
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7186 | if (valid >> 5 > invalid) |
| 51 | ✗ | return AVPROBE_SCORE_EXTENSION + 1; | |
| 52 | 7186 | return 0; | |
| 53 | } | ||
| 54 | |||
| 55 | ✗ | static int gsm_read_packet(AVFormatContext *s, AVPacket *pkt) | |
| 56 | { | ||
| 57 | int ret, size; | ||
| 58 | |||
| 59 | ✗ | size = GSM_BLOCK_SIZE; | |
| 60 | |||
| 61 | ✗ | pkt->pos = avio_tell(s->pb); | |
| 62 | ✗ | pkt->stream_index = 0; | |
| 63 | |||
| 64 | ✗ | ret = av_get_packet(s->pb, pkt, size); | |
| 65 | ✗ | if (ret < GSM_BLOCK_SIZE) { | |
| 66 | ✗ | return ret < 0 ? ret : AVERROR(EIO); | |
| 67 | } | ||
| 68 | ✗ | pkt->duration = 1; | |
| 69 | ✗ | pkt->pts = pkt->pos / GSM_BLOCK_SIZE; | |
| 70 | |||
| 71 | ✗ | return 0; | |
| 72 | } | ||
| 73 | |||
| 74 | ✗ | static int gsm_read_header(AVFormatContext *s) | |
| 75 | { | ||
| 76 | ✗ | GSMDemuxerContext *c = s->priv_data; | |
| 77 | ✗ | AVStream *st = avformat_new_stream(s, NULL); | |
| 78 | ✗ | if (!st) | |
| 79 | ✗ | return AVERROR(ENOMEM); | |
| 80 | |||
| 81 | ✗ | st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; | |
| 82 | ✗ | st->codecpar->codec_id = AV_CODEC_ID_GSM; | |
| 83 | ✗ | st->codecpar->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO; | |
| 84 | ✗ | st->codecpar->sample_rate = c->sample_rate; | |
| 85 | ✗ | st->codecpar->bit_rate = GSM_BLOCK_SIZE * 8 * c->sample_rate / GSM_BLOCK_SAMPLES; | |
| 86 | |||
| 87 | ✗ | avpriv_set_pts_info(st, 64, GSM_BLOCK_SAMPLES, GSM_SAMPLE_RATE); | |
| 88 | |||
| 89 | ✗ | return 0; | |
| 90 | } | ||
| 91 | |||
| 92 | static const AVOption options[] = { | ||
| 93 | { "sample_rate", "", offsetof(GSMDemuxerContext, sample_rate), | ||
| 94 | AV_OPT_TYPE_INT, {.i64 = GSM_SAMPLE_RATE}, 1, INT_MAX / GSM_BLOCK_SIZE, | ||
| 95 | AV_OPT_FLAG_DECODING_PARAM }, | ||
| 96 | { NULL }, | ||
| 97 | }; | ||
| 98 | |||
| 99 | static const AVClass gsm_class = { | ||
| 100 | .class_name = "gsm demuxer", | ||
| 101 | .item_name = av_default_item_name, | ||
| 102 | .option = options, | ||
| 103 | .version = LIBAVUTIL_VERSION_INT, | ||
| 104 | }; | ||
| 105 | |||
| 106 | const FFInputFormat ff_gsm_demuxer = { | ||
| 107 | .p.name = "gsm", | ||
| 108 | .p.long_name = NULL_IF_CONFIG_SMALL("raw GSM"), | ||
| 109 | .p.flags = AVFMT_GENERIC_INDEX, | ||
| 110 | .p.extensions = "gsm", | ||
| 111 | .p.priv_class = &gsm_class, | ||
| 112 | .priv_data_size = sizeof(GSMDemuxerContext), | ||
| 113 | .read_probe = gsm_probe, | ||
| 114 | .read_header = gsm_read_header, | ||
| 115 | .read_packet = gsm_read_packet, | ||
| 116 | .raw_codec_id = AV_CODEC_ID_GSM, | ||
| 117 | }; | ||
| 118 |