[FFmpeg-devel] [PATCH v3 3/7] lavf: APV demuxer

[Mark Thompson <sw@jkqxz.net>]

Demuxes raw streams as defined in draft spec section 10.2.
---
 libavformat/Makefile     |   1 +
 libavformat/allformats.c |   1 +
 libavformat/apvdec.c     | 241 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 243 insertions(+)
 create mode 100644 libavformat/apvdec.c

diff --git a/libavformat/Makefile b/libavformat/Makefile
index a94ac66e7e..ef96c2762e 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -119,6 +119,7 @@ OBJS-$(CONFIG_APTX_DEMUXER)              += aptxdec.o
 OBJS-$(CONFIG_APTX_MUXER)                += rawenc.o
 OBJS-$(CONFIG_APTX_HD_DEMUXER)           += aptxdec.o
 OBJS-$(CONFIG_APTX_HD_MUXER)             += rawenc.o
+OBJS-$(CONFIG_APV_DEMUXER)               += apvdec.o
 OBJS-$(CONFIG_AQTITLE_DEMUXER)           += aqtitledec.o subtitles.o
 OBJS-$(CONFIG_ARGO_ASF_DEMUXER)          += argo_asf.o
 OBJS-$(CONFIG_ARGO_ASF_MUXER)            += argo_asf.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 445f13f42a..90a4fe64ec 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -72,6 +72,7 @@ extern const FFInputFormat  ff_aptx_demuxer;
 extern const FFOutputFormat ff_aptx_muxer;
 extern const FFInputFormat  ff_aptx_hd_demuxer;
 extern const FFOutputFormat ff_aptx_hd_muxer;
+extern const FFInputFormat  ff_apv_demuxer;
 extern const FFInputFormat  ff_aqtitle_demuxer;
 extern const FFInputFormat  ff_argo_asf_demuxer;
 extern const FFOutputFormat ff_argo_asf_muxer;
diff --git a/libavformat/apvdec.c b/libavformat/apvdec.c
new file mode 100644
index 0000000000..04f9ef0a8f
--- /dev/null
+++ b/libavformat/apvdec.c
@@ -0,0 +1,241 @@
+/*
+ * 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 "libavcodec/apv.h"
+#include "libavcodec/bytestream.h"
+
+#include "avformat.h"
+#include "avio_internal.h"
+#include "demux.h"
+#include "internal.h"
+
+
+typedef struct APVHeaderInfo {
+    uint8_t  pbu_type;
+    uint16_t group_id;
+
+    uint8_t  profile_idc;
+    uint8_t  level_idc;
+    uint8_t  band_idc;
+
+    int      frame_width;
+    int      frame_height;
+
+    uint8_t  chroma_format_idc;
+    uint8_t  bit_depth_minus8;
+
+    enum AVPixelFormat pixel_format;
+} APVHeaderInfo;
+
+static const enum AVPixelFormat apv_format_table[5][5] = {
+    { AV_PIX_FMT_GRAY8,    AV_PIX_FMT_GRAY10,     AV_PIX_FMT_GRAY12,     AV_PIX_FMT_GRAY14, AV_PIX_FMT_GRAY16 },
+    { 0 }, // 4:2:0 is not valid.
+    { AV_PIX_FMT_YUV422P,  AV_PIX_FMT_YUV422P10,  AV_PIX_FMT_YUV422P12,  AV_PIX_FMT_GRAY14, AV_PIX_FMT_YUV422P16 },
+    { AV_PIX_FMT_YUV444P,  AV_PIX_FMT_YUV444P10,  AV_PIX_FMT_YUV444P12,  AV_PIX_FMT_GRAY14, AV_PIX_FMT_YUV444P16 },
+    { AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA444P10, AV_PIX_FMT_YUVA444P12, AV_PIX_FMT_GRAY14, AV_PIX_FMT_YUVA444P16 },
+};
+
+static int apv_extract_header_info(APVHeaderInfo *info,
+                                   GetByteContext *gbc)
+{
+    int zero, byte, bit_depth_index;
+
+    info->pbu_type = bytestream2_get_byte(gbc);
+    info->group_id = bytestream2_get_be16(gbc);
+
+    zero = bytestream2_get_byte(gbc);
+    if (zero != 0)
+        return AVERROR_INVALIDDATA;
+
+    if (info->pbu_type != APV_PBU_PRIMARY_FRAME)
+        return AVERROR_INVALIDDATA;
+
+    info->profile_idc = bytestream2_get_byte(gbc);
+    info->level_idc   = bytestream2_get_byte(gbc);
+
+    byte = bytestream2_get_byte(gbc);
+    info->band_idc = byte >> 3;
+    zero = byte & 7;
+    if (zero != 0)
+        return AVERROR_INVALIDDATA;
+
+    info->frame_width  = bytestream2_get_be24(gbc);
+    info->frame_height = bytestream2_get_be24(gbc);
+    if (info->frame_width  < 1 || info->frame_width  > 65536 ||
+        info->frame_height < 1 || info->frame_height > 65536)
+        return AVERROR_INVALIDDATA;
+
+    byte = bytestream2_get_byte(gbc);
+    info->chroma_format_idc = byte >> 4;
+    info->bit_depth_minus8  = byte & 0xf;
+
+    if (info->bit_depth_minus8 > 8) {
+        return AVERROR_INVALIDDATA;
+    }
+    if (info->bit_depth_minus8 % 2) {
+        // Odd bit depths are technically valid but not useful here.
+        return AVERROR_INVALIDDATA;
+    }
+    bit_depth_index = info->bit_depth_minus8 / 2;
+
+    switch (info->chroma_format_idc) {
+    case APV_CHROMA_FORMAT_400:
+    case APV_CHROMA_FORMAT_422:
+    case APV_CHROMA_FORMAT_444:
+    case APV_CHROMA_FORMAT_4444:
+        info->pixel_format = apv_format_table[info->chroma_format_idc][bit_depth_index];
+        break;
+    default:
+        return AVERROR_INVALIDDATA;
+    }
+
+    // Ignore capture_time_distance.
+    bytestream2_skip(gbc, 1);
+
+    zero = bytestream2_get_byte(gbc);
+    if (zero != 0)
+        return AVERROR_INVALIDDATA;
+
+    return 1;
+}
+
+static int apv_probe(const AVProbeData *p)
+{
+    GetByteContext gbc;
+    APVHeaderInfo header;
+    uint32_t au_size, signature, pbu_size;
+    int err;
+
+    if (p->buf_size < 28) {
+        // Too small to fit an APV header.
+        return 0;
+    }
+
+    bytestream2_init(&gbc, p->buf, p->buf_size);
+
+    au_size = bytestream2_get_be32(&gbc);
+    if (au_size < 24) {
+        // Too small.
+        return 0;
+    }
+    signature = bytestream2_get_be32(&gbc);
+    if (signature != APV_SIGNATURE) {
+        // Signature is mandatory.
+        return 0;
+    }
+    pbu_size = bytestream2_get_be32(&gbc);
+    if (pbu_size < 16) {
+        // Too small.
+        return 0;
+    }
+
+    err = apv_extract_header_info(&header, &gbc);
+    if (err < 0) {
+        // Header does not look like APV.
+        return 0;
+    }
+    return AVPROBE_SCORE_MAX;
+}
+
+static int apv_read_header(AVFormatContext *s)
+{
+    AVStream *st;
+    GetByteContext gbc;
+    APVHeaderInfo header;
+    uint8_t buffer[28];
+    uint32_t au_size, signature, pbu_size;
+    int err, size;
+
+    err = ffio_ensure_seekback(s->pb, sizeof(buffer));
+    if (err < 0)
+        return err;
+    size = avio_read(s->pb, buffer, sizeof(buffer));
+    if (size < 0)
+        return size;
+
+    bytestream2_init(&gbc, buffer, sizeof(buffer));
+
+    au_size = bytestream2_get_be32(&gbc);
+    if (au_size < 24) {
+        // Too small.
+        return AVERROR_INVALIDDATA;
+    }
+    signature = bytestream2_get_be32(&gbc);
+    if (signature != APV_SIGNATURE) {
+        // Signature is mandatory.
+        return AVERROR_INVALIDDATA;
+    }
+    pbu_size = bytestream2_get_be32(&gbc);
+    if (pbu_size < 16) {
+        // Too small.
+        return AVERROR_INVALIDDATA;
+    }
+
+    err = apv_extract_header_info(&header, &gbc);
+    if (err < 0)
+        return err;
+
+    st = avformat_new_stream(s, NULL);
+    if (!st)
+        return AVERROR(ENOMEM);
+
+    st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
+    st->codecpar->codec_id   = AV_CODEC_ID_APV;
+    st->codecpar->format     = header.pixel_format;
+    st->codecpar->profile    = header.profile_idc;
+    st->codecpar->level      = header.level_idc;
+    st->codecpar->width      = header.frame_width;
+    st->codecpar->height     = header.frame_height;
+
+    st->avg_frame_rate = (AVRational){ 30, 1 };
+    avpriv_set_pts_info(st, 64, 1, 30);
+
+    avio_seek(s->pb, -size, SEEK_CUR);
+
+    return 0;
+}
+
+static int apv_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    uint32_t au_size;
+    int ret;
+
+    au_size = avio_rb32(s->pb);
+    if (au_size == 0 && avio_feof(s->pb))
+        return AVERROR_EOF;
+    if (au_size < 16 || au_size > 1 << 24) {
+        av_log(s, AV_LOG_ERROR, "APV AU is bad\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    ret = av_get_packet(s->pb, pkt, au_size);
+    pkt->flags        = AV_PKT_FLAG_KEY;
+
+    return ret;
+}
+
+const FFInputFormat ff_apv_demuxer = {
+    .p.name         = "apv",
+    .p.long_name    = NULL_IF_CONFIG_SMALL("APV raw bitstream"),
+    .p.extensions   = "apv",
+    .p.flags        = AVFMT_GENERIC_INDEX | AVFMT_NOTIMESTAMPS,
+    .flags_internal = FF_INFMT_FLAG_INIT_CLEANUP,
+    .read_probe     = apv_probe,
+    .read_header    = apv_read_header,
+    .read_packet    = apv_read_packet,
+};
-- 
2.47.2

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