[FFmpeg-devel] [PATCH 2/4] avformat: add genh demuxer

Paul B Mahol onemda at gmail.com
Wed Oct 14 23:18:23 CEST 2015


Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
 libavformat/Makefile     |   1 +
 libavformat/allformats.c |   1 +
 libavformat/genh.c       | 176 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 178 insertions(+)
 create mode 100644 libavformat/genh.c

diff --git a/libavformat/Makefile b/libavformat/Makefile
index 2971912..a66bd17 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -177,6 +177,7 @@ OBJS-$(CONFIG_G722_MUXER)                += rawenc.o
 OBJS-$(CONFIG_G723_1_DEMUXER)            += g723_1.o
 OBJS-$(CONFIG_G723_1_MUXER)              += rawenc.o
 OBJS-$(CONFIG_G729_DEMUXER)              += g729dec.o
+OBJS-$(CONFIG_GENH_DEMUXER)              += genh.o
 OBJS-$(CONFIG_H261_DEMUXER)              += h261dec.o rawdec.o
 OBJS-$(CONFIG_H261_MUXER)                += rawenc.o
 OBJS-$(CONFIG_H263_DEMUXER)              += h263dec.o rawdec.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 0ccde9d..dbd7719 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -138,6 +138,7 @@ void av_register_all(void)
     REGISTER_MUXDEMUX(G722,             g722);
     REGISTER_MUXDEMUX(G723_1,           g723_1);
     REGISTER_DEMUXER (G729,             g729);
+    REGISTER_DEMUXER (GENH,             genh);
     REGISTER_MUXDEMUX(GIF,              gif);
     REGISTER_DEMUXER (GSM,              gsm);
     REGISTER_MUXDEMUX(GXF,              gxf);
diff --git a/libavformat/genh.c b/libavformat/genh.c
new file mode 100644
index 0000000..ce054b5
--- /dev/null
+++ b/libavformat/genh.c
@@ -0,0 +1,176 @@
+/*
+ * GENH demuxer
+ * Copyright (c) 2015 Paul B Mahol
+ *
+ * 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/intreadwrite.h"
+#include "avformat.h"
+#include "internal.h"
+
+typedef struct GENHDemuxContext {
+    unsigned dsp_int_type;
+    unsigned interleave_size;
+} GENHDemuxContext;
+
+static int genh_probe(AVProbeData *p)
+{
+    if (AV_RL32(p->buf) != MKTAG('G','E','N','H'))
+        return 0;
+
+    return AVPROBE_SCORE_MAX / 3 * 2;
+}
+
+static int genh_read_header(AVFormatContext *s)
+{
+    unsigned start_offset, header_size, codec, coef_type, coef[2];
+    GENHDemuxContext *c = s->priv_data;
+    unsigned coef_splitted[2];
+    int align, ch;
+    AVStream *st;
+
+    avio_skip(s->pb, 4);
+
+    st = avformat_new_stream(s, NULL);
+    if (!st)
+        return AVERROR(ENOMEM);
+
+    st->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
+    st->codec->channels    = avio_rl32(s->pb);
+    if (st->codec->channels <= 0)
+        return AVERROR_INVALIDDATA;
+    if (st->codec->channels == 1)
+        st->codec->channel_layout = AV_CH_LAYOUT_MONO;
+    else if (st->codec->channels == 2)
+        st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
+    align                  =
+    c->interleave_size     = avio_rl32(s->pb);
+    if (align < 0 || align > INT_MAX / st->codec->channels)
+        return AVERROR_INVALIDDATA;
+    st->codec->block_align = align * st->codec->channels;
+    st->codec->sample_rate = avio_rl32(s->pb);
+    avio_skip(s->pb, 4);
+    st->duration = avio_rl32(s->pb);
+
+    codec = avio_rl32(s->pb);
+    switch (codec) {
+    case  1:
+    case 11: st->codec->bits_per_coded_sample = 4;
+             st->codec->codec_id = AV_CODEC_ID_ADPCM_IMA_WAV;    break;
+    case  3: st->codec->codec_id = st->codec->block_align > 0 ?
+                                   AV_CODEC_ID_PCM_S16BE_PLANAR :
+                                   AV_CODEC_ID_PCM_S16BE;        break;
+    case  4: st->codec->codec_id = st->codec->block_align > 0 ?
+                                   AV_CODEC_ID_PCM_S16LE_PLANAR :
+                                   AV_CODEC_ID_PCM_S16LE;        break;
+    case  5: st->codec->codec_id = st->codec->block_align > 0 ?
+                                   AV_CODEC_ID_PCM_S8_PLANAR :
+                                   AV_CODEC_ID_PCM_S8;           break;
+    case 12: st->codec->codec_id = AV_CODEC_ID_ADPCM_THP;        break;
+    case 13: st->codec->codec_id = AV_CODEC_ID_PCM_U8;           break;
+    default:
+             avpriv_request_sample(s, "codec %d", codec);
+             return AVERROR_PATCHWELCOME;
+    }
+
+    start_offset = avio_rl32(s->pb);
+    header_size  = avio_rl32(s->pb);
+
+    if (header_size > start_offset)
+        return AVERROR_INVALIDDATA;
+
+    if (header_size == 0)
+        start_offset = 0x800;
+
+    coef[0]          = avio_rl32(s->pb);
+    coef[1]          = avio_rl32(s->pb);
+    c->dsp_int_type  = avio_rl32(s->pb);
+    coef_type        = avio_rl32(s->pb);
+    coef_splitted[0] = avio_rl32(s->pb);
+    coef_splitted[1] = avio_rl32(s->pb);
+
+    if (st->codec->codec_id == AV_CODEC_ID_ADPCM_THP) {
+        if (st->codec->channels > 2) {
+            avpriv_request_sample(s, "channels %d>2", st->codec->channels);
+            return AVERROR_PATCHWELCOME;
+        }
+
+        ff_alloc_extradata(st->codec, 32 * st->codec->channels);
+        for (ch = 0; ch < st->codec->channels; ch++) {
+            if (coef_type & 1) {
+                avpriv_request_sample(s, "coef_type & 1");
+                return AVERROR_PATCHWELCOME;
+            } else {
+                avio_seek(s->pb, coef[ch], SEEK_SET);
+                avio_read(s->pb, st->codec->extradata + 32 * ch, 32);
+            }
+        }
+
+        if (c->dsp_int_type == 1) {
+            st->codec->block_align = 8 * st->codec->channels;
+            if (c->interleave_size != 1 &&
+                c->interleave_size != 2 &&
+                c->interleave_size != 4)
+                return AVERROR_INVALIDDATA;
+        }
+    }
+
+    avio_skip(s->pb, start_offset - avio_tell(s->pb));
+
+    avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
+
+    return 0;
+}
+
+static int genh_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    AVCodecContext *codec = s->streams[0]->codec;
+    GENHDemuxContext *c = s->priv_data;
+    int ret;
+
+    if (c->dsp_int_type == 1 && codec->codec_id == AV_CODEC_ID_ADPCM_THP &&
+        codec->channels > 1) {
+        int i, ch;
+
+        if (avio_feof(s->pb))
+            return AVERROR_EOF;
+        av_new_packet(pkt, 8 * codec->channels);
+        for (i = 0; i < 8 / c->interleave_size; i++) {
+            for (ch = 0; ch < codec->channels; ch++) {
+                pkt->data[ch * 8 + i*c->interleave_size+0] = avio_r8(s->pb);
+                pkt->data[ch * 8 + i*c->interleave_size+1] = avio_r8(s->pb);
+            }
+        }
+        ret = 0;
+    } else {
+        ret = av_get_packet(s->pb, pkt, codec->block_align ? codec->block_align : 1024 * codec->channels);
+    }
+
+    pkt->stream_index = 0;
+    return ret;
+}
+
+AVInputFormat ff_genh_demuxer = {
+    .name           = "genh",
+    .long_name      = NULL_IF_CONFIG_SMALL("GENeric Header"),
+    .priv_data_size = sizeof(GENHDemuxContext),
+    .read_probe     = genh_probe,
+    .read_header    = genh_read_header,
+    .read_packet    = genh_read_packet,
+    .extensions     = "genh",
+};
-- 
1.9.1



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