early-access version 1432

externals/ffmpeg/libavformat/bit.c

@@ -0,0 +1,168 @@
+/*
+ * G.729 bit format muxer and demuxer
+ * Copyright (c) 2007-2008 Vladimir Voroshilov
+ *
+ * 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 "avformat.h"
+#include "internal.h"
+#include "libavcodec/get_bits.h"
+#include "libavcodec/put_bits.h"
+
+#define MAX_FRAME_SIZE 10
+
+#define SYNC_WORD  0x6b21
+#define BIT_0      0x7f
+#define BIT_1      0x81
+
+#if CONFIG_BIT_DEMUXER
+static int probe(const AVProbeData *p)
+{
+    int i = 0, j, valid = 0;
+
+    while (2 * i + 3 < p->buf_size){
+        if (AV_RL16(&p->buf[2 * i++]) != SYNC_WORD)
+            return 0;
+        j = AV_RL16(&p->buf[2 * i++]);
+        if (j != 0 && j != 0x10 && j != 0x40 && j != 0x50 && j != 0x76)
+            return 0;
+        if (j)
+            valid++;
+        i += j;
+    }
+    if (valid > 10)
+        return AVPROBE_SCORE_MAX;
+    if (valid > 2)
+        return AVPROBE_SCORE_EXTENSION - 1;
+    return 0;
+}
+
+static int read_header(AVFormatContext *s)
+{
+    AVStream* st;
+
+    st=avformat_new_stream(s, NULL);
+    if (!st)
+        return AVERROR(ENOMEM);
+
+    st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
+    st->codecpar->codec_id=AV_CODEC_ID_G729;
+    st->codecpar->sample_rate=8000;
+    st->codecpar->block_align = 16;
+    st->codecpar->channels=1;
+
+    avpriv_set_pts_info(st, 64, 1, 100);
+    return 0;
+}
+
+static int read_packet(AVFormatContext *s,
+                          AVPacket *pkt)
+{
+    AVIOContext *pb = s->pb;
+    PutBitContext pbo;
+    uint16_t buf[8 * MAX_FRAME_SIZE + 2];
+    int packet_size;
+    uint16_t* src=buf;
+    int i, j, ret;
+    int64_t pos= avio_tell(pb);
+
+    if(avio_feof(pb))
+        return AVERROR_EOF;
+
+    avio_rl16(pb); // sync word
+    packet_size = avio_rl16(pb) / 8;
+    if(packet_size > MAX_FRAME_SIZE)
+        return AVERROR_INVALIDDATA;
+
+    ret = avio_read(pb, (uint8_t*)buf, (8 * packet_size) * sizeof(uint16_t));
+    if(ret<0)
+        return ret;
+    if(ret != 8 * packet_size * sizeof(uint16_t))
+        return AVERROR(EIO);
+
+    if ((ret = av_new_packet(pkt, packet_size)) < 0)
+        return ret;
+
+    init_put_bits(&pbo, pkt->data, packet_size);
+    for(j=0; j < packet_size; j++)
+        for(i=0; i<8;i++)
+            put_bits(&pbo,1, AV_RL16(src++) == BIT_1 ? 1 : 0);
+
+    flush_put_bits(&pbo);
+
+    pkt->duration=1;
+    pkt->pos = pos;
+    return 0;
+}
+
+AVInputFormat ff_bit_demuxer = {
+    .name        = "bit",
+    .long_name   = NULL_IF_CONFIG_SMALL("G.729 BIT file format"),
+    .read_probe  = probe,
+    .read_header = read_header,
+    .read_packet = read_packet,
+    .extensions  = "bit",
+};
+#endif
+
+#if CONFIG_BIT_MUXER
+static int write_header(AVFormatContext *s)
+{
+    AVCodecParameters *par = s->streams[0]->codecpar;
+
+    if ((par->codec_id != AV_CODEC_ID_G729) || par->channels != 1) {
+        av_log(s, AV_LOG_ERROR,
+               "only codec g729 with 1 channel is supported by this format\n");
+        return AVERROR(EINVAL);
+    }
+
+    par->bits_per_coded_sample = 16;
+    par->block_align = (par->bits_per_coded_sample * par->channels) >> 3;
+
+    return 0;
+}
+
+static int write_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    AVIOContext *pb = s->pb;
+    GetBitContext gb;
+    int i;
+
+    if (pkt->size != 10)
+        return AVERROR(EINVAL);
+
+    avio_wl16(pb, SYNC_WORD);
+    avio_wl16(pb, 8 * pkt->size);
+
+    init_get_bits(&gb, pkt->data, 8 * pkt->size);
+    for (i = 0; i < 8 * pkt->size; i++)
+        avio_wl16(pb, get_bits1(&gb) ? BIT_1 : BIT_0);
+
+    return 0;
+}
+
+AVOutputFormat ff_bit_muxer = {
+    .name         = "bit",
+    .long_name    = NULL_IF_CONFIG_SMALL("G.729 BIT file format"),
+    .mime_type    = "audio/bit",
+    .extensions   = "bit",
+    .audio_codec  = AV_CODEC_ID_G729,
+    .video_codec  = AV_CODEC_ID_NONE,
+    .write_header = write_header,
+    .write_packet = write_packet,
+};
+#endif