[FFmpeg-devel] [PATCH] avformat: add DHAV demuxer

Paul B Mahol onemda at gmail.com
Fri Nov 23 23:02:03 EET 2018


Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
 libavformat/Makefile     |   1 +
 libavformat/allformats.c |   1 +
 libavformat/dhav.c       | 250 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 252 insertions(+)
 create mode 100644 libavformat/dhav.c

diff --git a/libavformat/Makefile b/libavformat/Makefile
index e4d997c4a0..a6c5ea9aa3 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -149,6 +149,7 @@ OBJS-$(CONFIG_DAUD_DEMUXER)              += dauddec.o
 OBJS-$(CONFIG_DAUD_MUXER)                += daudenc.o
 OBJS-$(CONFIG_DCSTR_DEMUXER)             += dcstr.o
 OBJS-$(CONFIG_DFA_DEMUXER)               += dfa.o
+OBJS-$(CONFIG_DHAV_DEMUXER)              += dhav.o
 OBJS-$(CONFIG_DIRAC_DEMUXER)             += diracdec.o rawdec.o
 OBJS-$(CONFIG_DIRAC_MUXER)               += rawenc.o
 OBJS-$(CONFIG_DNXHD_DEMUXER)             += dnxhddec.o rawdec.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 498077e1de..5fb5bf17c6 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -110,6 +110,7 @@ extern AVInputFormat  ff_daud_demuxer;
 extern AVOutputFormat ff_daud_muxer;
 extern AVInputFormat  ff_dcstr_demuxer;
 extern AVInputFormat  ff_dfa_demuxer;
+extern AVInputFormat  ff_dhav_demuxer;
 extern AVInputFormat  ff_dirac_demuxer;
 extern AVOutputFormat ff_dirac_muxer;
 extern AVInputFormat  ff_dnxhd_demuxer;
diff --git a/libavformat/dhav.c b/libavformat/dhav.c
new file mode 100644
index 0000000000..2b523dc402
--- /dev/null
+++ b/libavformat/dhav.c
@@ -0,0 +1,250 @@
+/*
+ * DHAV demuxer
+ *
+ * Copyright (c) 2018 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/avassert.h"
+#include "avformat.h"
+#include "internal.h"
+
+typedef struct DHAVContext {
+    unsigned type;
+    int width, height;
+    int video_codec;
+    int frame_rate;
+    int channels;
+    int audio_codec;
+    int sample_rate;
+    int64_t pts;
+
+    int video_stream_index;
+    int audio_stream_index;
+} DHAVContext;
+
+static int dhav_probe(AVProbeData *p)
+{
+    if (memcmp(p->buf, "DHAV", 4))
+        return 0;
+
+    return AVPROBE_SCORE_MAX;
+}
+
+static int dhav_read_header(AVFormatContext *s)
+{
+    DHAVContext *dhav = s->priv_data;
+
+    s->ctx_flags |= AVFMTCTX_NOHEADER;
+    dhav->video_stream_index = -1;
+    dhav->audio_stream_index = -1;
+
+    return 0;
+}
+
+static const uint16_t sample_rates[] = {
+    8000, 4000, 8000, 11025, 16000,
+    20000, 22050, 32000, 44100, 48000,
+};
+
+static int parse_ext(AVFormatContext *s, int length)
+{
+    DHAVContext *dhav = s->priv_data;
+    int index;
+
+    while (length > 0) {
+        int type = avio_r8(s->pb);
+
+        switch (type) {
+        case 0x80:
+            avio_skip(s->pb, 1);
+            dhav->width  = 8 * avio_r8(s->pb);
+            dhav->height = 8 * avio_r8(s->pb);
+            length -= 4;
+            break;
+        case 0x81:
+            avio_skip(s->pb, 1);
+            dhav->video_codec = avio_r8(s->pb);
+            dhav->frame_rate = avio_r8(s->pb);
+            length -= 4;
+            break;
+        case 0x82:
+            avio_skip(s->pb, 3);
+            dhav->width  = avio_rl16(s->pb);
+            dhav->height = avio_rl16(s->pb);
+            length -= 8;
+            break;
+        case 0x83:
+            dhav->channels = avio_r8(s->pb);
+            dhav->audio_codec = avio_r8(s->pb);
+            index = avio_r8(s->pb);
+            if (index < 10) {
+                dhav->sample_rate = sample_rates[index];
+            } else {
+                dhav->sample_rate = 8000;
+            }
+            length -= 4;
+            break;
+        case 0x88:
+            avio_skip(s->pb, 7);
+            length -= 8;
+            break;
+        case 0x91:
+        case 0x92:
+        case 0x93:
+        case 0x95:
+        case 0x9a:
+            avio_skip(s->pb, 7);
+            length -= 8;
+            break;
+        case 0x8b:
+        case 0x94:
+        case 0x96:
+            avio_skip(s->pb, 3);
+            length -= 4;
+            break;
+        default:
+            av_log(s, AV_LOG_INFO, "Unknown type: %X, skipping rest of header.\n", type);
+            avio_skip(s->pb, length - 1);
+            length = 0;
+        }
+    }
+
+    return 0;
+}
+
+static int read_chunk(AVFormatContext *s)
+{
+    DHAVContext *dhav = s->priv_data;
+    unsigned size, skip;
+    int64_t start, end;
+    int ret;
+
+    start = avio_tell(s->pb);
+
+    if (avio_feof(s->pb))
+        return AVERROR_EOF;
+
+    if (avio_rl32(s->pb) != MKTAG('D','H','A','V'))
+        return AVERROR_INVALIDDATA;
+
+    dhav->type = avio_r8(s->pb);
+    avio_skip(s->pb, 3);
+    dhav->pts = avio_rl32(s->pb);
+    size = avio_rl32(s->pb);
+    if (size < 24)
+        return AVERROR_INVALIDDATA;
+    if (dhav->type == 0xf1) {
+        avio_skip(s->pb, size - 16);
+        return 0;
+    }
+
+    avio_rl32(s->pb);
+    avio_skip(s->pb, 2);
+    skip = avio_r8(s->pb);
+    avio_skip(s->pb, 1);
+
+    ret = parse_ext(s, skip);
+    if (ret < 0)
+        return ret;
+
+    end = avio_tell(s->pb);
+
+    return size - 8 - (end - start);
+}
+
+static int dhav_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    DHAVContext *dhav = s->priv_data;
+    int64_t start;
+    int ret;
+
+    start = avio_tell(s->pb);
+
+    while ((ret = read_chunk(s)) == 0)
+        ;
+
+    if (ret < 0)
+        return ret;
+
+    if (dhav->type == 0xfd && dhav->video_stream_index == -1) {
+        AVStream *st = avformat_new_stream(s, NULL);
+
+        if (!st)
+            return AVERROR(ENOMEM);
+
+        st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
+        switch (dhav->video_codec) {
+        case 0x1: st->codecpar->codec_id = AV_CODEC_ID_MPEG4; break;
+        case 0x3: st->codecpar->codec_id = AV_CODEC_ID_MJPEG; break;
+        case 0x2:
+        case 0x4:
+        case 0x8: st->codecpar->codec_id = AV_CODEC_ID_H264;  break;
+        case 0xc: st->codecpar->codec_id = AV_CODEC_ID_HEVC;  break;
+        default: avpriv_request_sample(s, "Unknown video codec %X\n", dhav->video_codec);
+        }
+        st->codecpar->width      = dhav->width;
+        st->codecpar->height     = dhav->height;
+        dhav->video_stream_index = st->index;
+
+        avpriv_set_pts_info(st, 64, 1, dhav->frame_rate);
+    } else if (dhav->type == 0xf0 && dhav->audio_stream_index == -1) {
+        AVStream *st = avformat_new_stream(s, NULL);
+
+        if (!st)
+            return AVERROR(ENOMEM);
+
+        st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
+        switch (dhav->audio_codec) {
+        case 0x16: st->codecpar->codec_id = AV_CODEC_ID_PCM_MULAW; break;
+        case 0x0e: st->codecpar->codec_id = AV_CODEC_ID_PCM_ALAW;  break;
+        default: avpriv_request_sample(s, "Unknown audio codec %X\n", dhav->audio_codec);
+        }
+        st->codecpar->channels    = dhav->channels;
+        st->codecpar->sample_rate = dhav->sample_rate;
+        dhav->audio_stream_index  = st->index;
+
+        avpriv_set_pts_info(st, 64, ret, dhav->sample_rate);
+    }
+
+    ret = av_get_packet(s->pb, pkt, ret);
+    if (ret < 0)
+        return ret;
+    pkt->stream_index = dhav->type == 0xf0 ? dhav->audio_stream_index : dhav->video_stream_index;
+    if (dhav->type != 0xfc)
+        pkt->flags   |= AV_PKT_FLAG_KEY;
+    pkt->pts = dhav->pts;
+    pkt->duration = 1;
+    pkt->pos = start;
+    if (avio_rl32(s->pb) != MKTAG('d','h','a','v'))
+        return AVERROR_INVALIDDATA;
+    avio_skip(s->pb, 4);
+
+    return ret;
+}
+
+AVInputFormat ff_dhav_demuxer = {
+    .name           = "dhav",
+    .long_name      = NULL_IF_CONFIG_SMALL("Video DAV"),
+    .priv_data_size = sizeof(DHAVContext),
+    .read_probe     = dhav_probe,
+    .read_header    = dhav_read_header,
+    .read_packet    = dhav_read_packet,
+    .extensions     = "dav",
+    .flags          = AVFMT_GENERIC_INDEX | AVFMT_NO_BYTE_SEEK,
+};
-- 
2.17.1



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