avcodec/hapqa_extract_bsf : add new bsf filter

convert HapQA data to HAPQ or HAPAlphaOnly
by copying the corresponding texture

1 files changed, 135 insertions, 0 deletions

diff --git a/libavcodec/hapqa_extract_bsf.c b/libavcodec/hapqa_extract_bsf.c
new file mode 100644
index 0000000..45fe9fb
--- /dev/null
+++ b/libavcodec/hapqa_extract_bsf.c
@@ -0,0 +1,135 @@
+/*
+ * HAPQA extract bitstream filter
+ * Copyright (c) 2017 Jokyo Images
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * HAPQA extract bitstream filter
+ * extract one of the two textures of the HAQA
+ */
+
+#include "avcodec.h"
+#include "bsf.h"
+#include "bytestream.h"
+#include "hap.h"
+
+typedef struct HapqaExtractContext {
+    const AVClass *class;
+    int texture;/* index of the texture to keep (0 for rgb or 1 for alpha) */
+} HapqaExtractContext;
+
+static int check_texture(HapqaExtractContext *ctx, int section_type) {
+    if (((ctx->texture == 0)&&((section_type & 0x0F) == 0x0F)) || /* HapQ texture and rgb extract */
+        ((ctx->texture == 1)&&((section_type & 0x0F) == 0x01))) /* HapAlphaOnly texture and alpha extract */
+    {
+        return 1; /* the texture is the one to keep */
+    } else {
+        return 0;
+    }
+}
+
+static int hapqa_extract(AVBSFContext *bsf, AVPacket *out)
+{
+    HapqaExtractContext *ctx = bsf->priv_data;
+    GetByteContext gbc;
+    int section_size;
+    enum HapSectionType section_type;
+    int start_section_size;
+    int target_packet_size = 0;
+    AVPacket *in;
+    int ret = 0;
+
+    ret = ff_bsf_get_packet(bsf, &in);
+    if (ret < 0)
+        return ret;
+
+    bytestream2_init(&gbc, in->data, in->size);
+    ret = ff_hap_parse_section_header(&gbc, &section_size, &section_type);
+    if (ret != 0)
+        goto fail;
+
+    if ((section_type & 0x0F) != 0x0D) {
+        av_log(bsf, AV_LOG_ERROR, "Invalid section type for HAPQA %#04x.\n", section_type & 0x0F);
+        goto fail;
+    }
+
+    start_section_size = 4;
+
+    bytestream2_seek(&gbc, start_section_size, SEEK_SET);/* go to start of the first texture */
+
+    ret = ff_hap_parse_section_header(&gbc, &section_size, &section_type);
+    if (ret != 0)
+        goto fail;
+
+    target_packet_size = section_size + 4;
+
+    if (check_texture(ctx, section_type) == 0) { /* the texture is not the one to keep */
+        start_section_size += 4 + section_size;
+        bytestream2_seek(&gbc, start_section_size, SEEK_SET);/* go to start of the second texture */
+        ret = ff_hap_parse_section_header(&gbc, &section_size, &section_type);
+        if (ret != 0)
+            goto fail;
+
+        target_packet_size = section_size + 4;
+
+        if (check_texture(ctx, section_type) == 0){ /* the second texture is not the one to keep */
+            av_log(bsf, AV_LOG_ERROR, "No valid texture found.\n");
+            goto fail;
+        }
+    }
+
+    av_packet_move_ref(out, in);
+    out->data += start_section_size;
+    out->size = target_packet_size;
+
+fail:
+    if (ret < 0)
+        av_packet_unref(out);
+    av_packet_free(&in);
+    return ret;
+}
+
+static const enum AVCodecID codec_ids[] = {
+    AV_CODEC_ID_HAP, AV_CODEC_ID_NONE,
+};
+
+#define OFFSET(x) offsetof(HapqaExtractContext, x)
+#define FLAGS     AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
+static const AVOption options[] = {
+    { "texture", "texture to keep", OFFSET(texture), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, FLAGS,  "texture" },
+        { "color", "keep HapQ texture", 0, AV_OPT_TYPE_CONST, { .i64 = 0 }, 0, 0, FLAGS, "texture" },
+        { "alpha", "keep HapAlphaOnly texture", 0, AV_OPT_TYPE_CONST, { .i64 = 1 }, 0, 0, FLAGS, "texture" },
+    { NULL },
+};
+
+static const AVClass hapqa_extract_class = {
+    .class_name = "hapqa_extract_bsf",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_MAJOR,
+};
+
+const AVBitStreamFilter ff_hapqa_extract_bsf = {
+    .name       = "hapqa_extract",
+    .filter     = hapqa_extract,
+    .priv_data_size = sizeof(HapqaExtractContext),
+    .priv_class = &hapqa_extract_class,
+    .codec_ids  = codec_ids,
+};