[v2,3/5] Implement the iLBC storage file format

Message ID 1340008803-89076-3-git-send-email-martin@martin.st
State Committed
Headers show

Commit Message

Martin Storsjö June 18, 2012, 8:40 a.m.
---
 doc/general.texi         |    1 +
 libavformat/Makefile     |    2 +
 libavformat/allformats.c |    1 +
 libavformat/ilbc.c       |  140 ++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 144 insertions(+)
 create mode 100644 libavformat/ilbc.c

Comments

Justin Ruggles June 18, 2012, 2:38 p.m. | #1
On 06/18/2012 04:40 AM, Martin Storsjö wrote:
> ---
>  doc/general.texi         |    1 +
>  libavformat/Makefile     |    2 +
>  libavformat/allformats.c |    1 +
>  libavformat/ilbc.c       |  140 ++++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 144 insertions(+)
>  create mode 100644 libavformat/ilbc.c
[...]
> +AVOutputFormat ff_ilbc_muxer = {
> +    .name         = "ilbc",
> +    .long_name    = NULL_IF_CONFIG_SMALL("iLBC storage file format"),
> +    .mime_type    = "audio/iLBC",
> +    .extensions   = "lbc",
> +    .audio_codec  = CODEC_ID_ILBC,
> +    .write_header = ilbc_write_header,
> +    .write_packet = ilbc_write_packet,
> +};

Since this raw format has no coded timestamps, it should use the
AVFMT_NOTIMESTAMPS flag.

The rest LGTM.

-Justin

Patch

diff --git a/doc/general.texi b/doc/general.texi
index 0c600ce..82a181c 100644
--- a/doc/general.texi
+++ b/doc/general.texi
@@ -184,6 +184,7 @@  library:
 @item IEC61937 encapsulation @tab X @tab X
 @item IFF                       @tab   @tab X
     @tab Interchange File Format
+@item iLBC                      @tab X @tab X
 @item Interplay MVE             @tab   @tab X
     @tab Format used in various Interplay computer games.
 @item IV8                       @tab   @tab X
diff --git a/libavformat/Makefile b/libavformat/Makefile
index 6262324..88e8db4 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -110,6 +110,8 @@  OBJS-$(CONFIG_H264_MUXER)                += rawenc.o
 OBJS-$(CONFIG_HLS_DEMUXER)               += hls.o
 OBJS-$(CONFIG_IDCIN_DEMUXER)             += idcin.o
 OBJS-$(CONFIG_IFF_DEMUXER)               += iff.o
+OBJS-$(CONFIG_ILBC_DEMUXER)              += ilbc.o
+OBJS-$(CONFIG_ILBC_MUXER)                += ilbc.o
 OBJS-$(CONFIG_IMAGE2_DEMUXER)            += img2dec.o img2.o
 OBJS-$(CONFIG_IMAGE2_MUXER)              += img2enc.o img2.o
 OBJS-$(CONFIG_IMAGE2PIPE_DEMUXER)        += img2dec.o img2.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 42c588f..8456398 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -108,6 +108,7 @@  void av_register_all(void)
     REGISTER_DEMUXER  (HLS, hls);
     REGISTER_DEMUXER  (IDCIN, idcin);
     REGISTER_DEMUXER  (IFF, iff);
+    REGISTER_MUXDEMUX (ILBC, ilbc);
     REGISTER_MUXDEMUX (IMAGE2, image2);
     REGISTER_MUXDEMUX (IMAGE2PIPE, image2pipe);
     REGISTER_DEMUXER  (INGENIENT, ingenient);
diff --git a/libavformat/ilbc.c b/libavformat/ilbc.c
new file mode 100644
index 0000000..5d0483c
--- /dev/null
+++ b/libavformat/ilbc.c
@@ -0,0 +1,140 @@ 
+/*
+ * iLBC storage file format
+ * Copyright (c) 2012 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 "avformat.h"
+#include "internal.h"
+
+static const char mode20_header[] = "#!iLBC20\n";
+static const char mode30_header[] = "#!iLBC30\n";
+
+static int ilbc_write_header(AVFormatContext *s)
+{
+    AVIOContext *pb = s->pb;
+    AVCodecContext *enc;
+
+    if (s->nb_streams != 1) {
+        av_log(s, AV_LOG_ERROR, "Unsupported number of streams\n");
+        return AVERROR(EINVAL);
+    }
+    enc = s->streams[0]->codec;
+
+    if (enc->codec_id != CODEC_ID_ILBC) {
+        av_log(s, AV_LOG_ERROR, "Unsupported codec\n");
+        return AVERROR(EINVAL);
+    }
+
+    if (enc->block_align == 50) {
+        avio_write(pb, mode30_header, sizeof(mode30_header) - 1);
+    } else if (enc->block_align == 38) {
+        avio_write(pb, mode20_header, sizeof(mode20_header) - 1);
+    } else {
+        av_log(s, AV_LOG_ERROR, "Unsupported mode\n");
+        return AVERROR(EINVAL);
+    }
+    avio_flush(pb);
+    return 0;
+}
+
+static int ilbc_write_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    avio_write(s->pb, pkt->data, pkt->size);
+    avio_flush(s->pb);
+    return 0;
+}
+
+static int ilbc_probe(AVProbeData *p)
+{
+    // Only check for "#!iLBC" which matches both formats
+    if (!memcmp(p->buf, mode20_header, 6))
+        return AVPROBE_SCORE_MAX;
+    else
+        return 0;
+}
+
+static int ilbc_read_header(AVFormatContext *s)
+{
+    AVIOContext *pb = s->pb;
+    AVStream *st;
+    uint8_t header[9];
+
+    avio_read(pb, header, 9);
+
+    st = avformat_new_stream(s, NULL);
+    if (!st)
+        return AVERROR(ENOMEM);
+    st->codec->codec_id = CODEC_ID_ILBC;
+    st->codec->sample_rate = 8000;
+    st->codec->channels = 1;
+    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
+    st->start_time = 0;
+    avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
+    if (!memcmp(header, mode20_header, sizeof(mode20_header) - 1)) {
+        st->codec->block_align = 38;
+        st->codec->bit_rate = 15200;
+    } else if (!memcmp(header, mode30_header, sizeof(mode30_header) - 1)) {
+        st->codec->block_align = 50;
+        st->codec->bit_rate = 13333;
+    } else {
+        av_log(s, AV_LOG_ERROR, "Unrecognized iLBC file header\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    return 0;
+}
+
+static int ilbc_read_packet(AVFormatContext *s,
+                          AVPacket *pkt)
+{
+    AVCodecContext *enc = s->streams[0]->codec;
+    int ret;
+
+    if ((ret = av_new_packet(pkt, enc->block_align)) < 0)
+        return ret;
+
+    pkt->stream_index = 0;
+    pkt->pos = avio_tell(s->pb);
+    pkt->duration = enc->block_align == 38 ? 160 : 240;
+    if ((ret = avio_read(s->pb, pkt->data, enc->block_align)) != enc->block_align) {
+        av_free_packet(pkt);
+        return ret < 0 ? ret : AVERROR(EIO);
+    }
+
+    return 0;
+}
+
+AVInputFormat ff_ilbc_demuxer = {
+    .name         = "ilbc",
+    .long_name    = NULL_IF_CONFIG_SMALL("iLBC storage file format"),
+    .read_probe   = ilbc_probe,
+    .read_header  = ilbc_read_header,
+    .read_packet  = ilbc_read_packet,
+    .flags        = AVFMT_GENERIC_INDEX,
+};
+
+AVOutputFormat ff_ilbc_muxer = {
+    .name         = "ilbc",
+    .long_name    = NULL_IF_CONFIG_SMALL("iLBC storage file format"),
+    .mime_type    = "audio/iLBC",
+    .extensions   = "lbc",
+    .audio_codec  = CODEC_ID_ILBC,
+    .write_header = ilbc_write_header,
+    .write_packet = ilbc_write_packet,
+};