[FFmpeg-devel] [PATCH] Extract QP from h264 encoded videos

Juan De León juandl at google.com
Wed Jul 24 22:18:59 EEST 2019


---
 libavcodec/avcodec.h            |   1 +
 libavcodec/h264dec.c            |  37 ++++++++++++
 libavcodec/options_table.h      |   1 +
 libavutil/Makefile              |   2 +
 libavutil/frame.h               |   6 ++
 libavutil/quantization_params.c |  40 +++++++++++++
 libavutil/quantization_params.h | 102 ++++++++++++++++++++++++++++++++
 7 files changed, 189 insertions(+)
 create mode 100644 libavutil/quantization_params.c
 create mode 100644 libavutil/quantization_params.h

diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index d234271c5b..9e3185720a 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -2671,6 +2671,7 @@ typedef struct AVCodecContext {
 #endif
 #define FF_DEBUG_BUFFERS     0x00008000
 #define FF_DEBUG_THREADS     0x00010000
+#define FF_DEBUG_EXTRACTQP   0x00020000
 #define FF_DEBUG_GREEN_MD    0x00800000
 #define FF_DEBUG_NOMC        0x01000000
 
diff --git a/libavcodec/h264dec.c b/libavcodec/h264dec.c
index 8d1bd16a8e..07b85f4e0a 100644
--- a/libavcodec/h264dec.c
+++ b/libavcodec/h264dec.c
@@ -33,6 +33,7 @@
 #include "libavutil/opt.h"
 #include "libavutil/stereo3d.h"
 #include "libavutil/timer.h"
+#include "libavutil/quantization_params.h"
 #include "internal.h"
 #include "bytestream.h"
 #include "cabac.h"
@@ -922,6 +923,42 @@ static int finalize_frame(H264Context *h, AVFrame *dst, H264Picture *out, int *g
         }
     }
 
+    if (h->avctx->debug & FF_DEBUG_EXTRACTQP) {
+        int mb_height = h->height / 16;
+        int mb_width = h->width / 16;
+        int mb_xy = mb_width * mb_height;
+
+        AVFrameSideData *sd;
+        sd = av_frame_new_side_data(dst, AV_FRAME_DATA_QUANTIZATION_PARAMS,
+                                  sizeof(AVQuantizationParamsArray));
+
+        AVQuantizationParamsArray *params;
+        params = (AVQuantizationParamsArray *)sd->data;
+        params->nb_blocks = mb_xy;
+        params->qp_arr = av_malloc_array(mb_xy, sizeof(AVQuantizationParams));
+
+        params->codec_id = h->avctx->codec_id;
+
+        // loop allocate QP
+        int qp_index = 0;
+        for (int mb_y = 0; mb_y < mb_height; mb_y++) {
+            for (int mb_x = 0; mb_x < mb_width; mb_x++) {
+                int qs_index = mb_x + mb_y * h->mb_stride;
+                AVQuantizationParams *qp_block = &(params->qp_arr[qp_index]);
+
+                qp_block->x = mb_x * 16;
+                qp_block->y = mb_y * 16;
+                qp_block->w = qp_block->h = 16;
+
+                // ALLOCATE MEMORY TO THE QP ARRAY
+                qp_block->type = av_malloc(QP_TYPE_ARR_SIZE_H264 * sizeof(int));
+                qp_block->type[QP_H264] = out->qscale_table[qs_index];
+
+                qp_index++;
+            }
+        }
+    }
+    
     return 0;
 }
 
diff --git a/libavcodec/options_table.h b/libavcodec/options_table.h
index 4a266eca16..e0e78a69c5 100644
--- a/libavcodec/options_table.h
+++ b/libavcodec/options_table.h
@@ -219,6 +219,7 @@ static const AVOption avcodec_options[] = {
 {"buffers", "picture buffer allocations", 0, AV_OPT_TYPE_CONST, {.i64 = FF_DEBUG_BUFFERS }, INT_MIN, INT_MAX, V|D, "debug"},
 {"thread_ops", "threading operations", 0, AV_OPT_TYPE_CONST, {.i64 = FF_DEBUG_THREADS }, INT_MIN, INT_MAX, V|A|D, "debug"},
 {"nomc", "skip motion compensation", 0, AV_OPT_TYPE_CONST, {.i64 = FF_DEBUG_NOMC }, INT_MIN, INT_MAX, V|A|D, "debug"},
+{"extractqp", "enable QP extraction per frame", 0, AV_OPT_TYPE_CONST, {.i64 = FF_DEBUG_EXTRACTQP }, INT_MIN, INT_MAX, V|D, "debug"},
 {"dia_size", "diamond type & size for motion estimation", OFFSET(dia_size), AV_OPT_TYPE_INT, {.i64 = DEFAULT }, INT_MIN, INT_MAX, V|E},
 {"last_pred", "amount of motion predictors from the previous frame", OFFSET(last_predictor_count), AV_OPT_TYPE_INT, {.i64 = DEFAULT }, INT_MIN, INT_MAX, V|E},
 #if FF_API_PRIVATE_OPT
diff --git a/libavutil/Makefile b/libavutil/Makefile
index 8a7a44e4b5..be1a9c3a9c 100644
--- a/libavutil/Makefile
+++ b/libavutil/Makefile
@@ -60,6 +60,7 @@ HEADERS = adler32.h                                                     \
           pixdesc.h                                                     \
           pixelutils.h                                                  \
           pixfmt.h                                                      \
+          quantization_params.h                                         \
           random_seed.h                                                 \
           rc4.h                                                         \
           rational.h                                                    \
@@ -140,6 +141,7 @@ OBJS = adler32.o                                                        \
        parseutils.o                                                     \
        pixdesc.o                                                        \
        pixelutils.o                                                     \
+       quantization_params.o                                            \
        random_seed.o                                                    \
        rational.o                                                       \
        reverse.o                                                        \
diff --git a/libavutil/frame.h b/libavutil/frame.h
index 5d3231e7bb..d48ccf342f 100644
--- a/libavutil/frame.h
+++ b/libavutil/frame.h
@@ -179,6 +179,12 @@ enum AVFrameSideDataType {
      * array element is implied by AVFrameSideData.size / AVRegionOfInterest.self_size.
      */
     AV_FRAME_DATA_REGIONS_OF_INTEREST,
+    /**
+     * To extract quantization parameters from supported decoders.
+     * The data stored is AVQuantizationParamsArray type, described in
+     * libavuitls/quantization_params.h
+     */
+    AV_FRAME_DATA_QUANTIZATION_PARAMS,
 };
 
 enum AVActiveFormatDescription {
diff --git a/libavutil/quantization_params.c b/libavutil/quantization_params.c
new file mode 100644
index 0000000000..230a9869bb
--- /dev/null
+++ b/libavutil/quantization_params.c
@@ -0,0 +1,40 @@
+/*
+ * 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/quantization_params.h"
+/**
+ * Strings for names of enums, used by Filter
+ */
+const char* const QP_NAMES_H264[] = {"qp"};
+const char* const QP_NAMES_VP9[] = {"qydc", "qyac", "quvdc", "quvac", "qiydc", "qiyac",
+                              "qiuvdc", "qiuvac"};
+const char* const QP_NAMES_AV1[] = {"qydc", "qyac", "qudc", "quac", "qvdc", "qvac",
+                              "qiydc", "qiyac", "qiudc", "qiuac", "qivdc", "qivac"};
+
+char* getQPTypeStr(enum AVCodecID codec_id, int index) {
+    switch (codec_id) {
+        case AV_CODEC_ID_H264:
+            return QP_NAMES_H264[index];
+        case AV_CODEC_ID_VP9:
+            return QP_NAMES_VP9[index];
+        case AV_CODEC_ID_AV1:
+            return QP_NAMES_AV1[index];
+        default:
+            return NULL;
+    }
+}
diff --git a/libavutil/quantization_params.h b/libavutil/quantization_params.h
new file mode 100644
index 0000000000..a48c472143
--- /dev/null
+++ b/libavutil/quantization_params.h
@@ -0,0 +1,102 @@
+/*
+ * 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
+ */
+
+#ifndef AVUTIL_QUANTIZATION_PARAMS_H
+#define AVUTIL_QUANTIZATION_PARAMS_H
+
+#include "libavcodec/avcodec.h"
+
+/**
+ * Data structure for extracting Quantization Parameters codec independent
+ */
+typedef struct AVQuantizationParams {
+    /**
+     * x and y coordinates of the block in pixels
+     */
+    int x, y;
+    /**
+     * width and height of the block in pixels
+     */
+    int w, h;
+    /**
+     * qp array, indexed by type according to
+     * the enum corresponding to the codec
+     * size depends on codec
+     */
+    int *type;
+} AVQuantizationParams;
+
+/**
+ * For storing an array of AVQuantization parameters and its size
+ * To be used as AVFrameSideData
+ */
+typedef struct AVQuantizationParamsArray {
+    /**
+     * AVQuantizationParams block array
+     */
+    AVQuantizationParams *qp_arr;
+    /**
+     * size of the array
+     */
+    int nb_blocks;
+    int codec_id;
+} AVQuantizationParamsArray;
+
+/**
+ * Enums for different codecs to store qp in the type array
+ * Each enum must have an array of strings describing each field
+ */
+char* getQPTypeStr(enum AVCodecID codec_id, int index);
+
+extern const char* const QP_NAMES_H264[];
+enum QP_ARR_INDEXES_FOR_H264 {
+        QP_H264 = 0,            // qp value
+        QP_TYPE_ARR_SIZE_H264   // used for allocating memory
+};
+
+extern const char* const QP_NAMES_VP9[];
+enum QP_ARR_INDEXES_FOR_VP9 {
+        QP_YDC_VP9 = 0,
+        QP_YAC_VP9,
+        QP_UVDC_VP9,
+        QP_UVAC_VP9,
+        QP_INDEX_YDC_VP9,
+        QP_INDEX_YAC_VP9,
+        QP_INDEX_UVDC_VP9,
+        QP_INDEX_UVAC_VP9,
+        QP_ARR_SIZE_VP9
+};
+
+extern const char* const QP_NAMES_AV1[];
+enum QP_ARR_INDEXES_FOR_AV1 {
+        QP_YDC_AV1 = 0,
+        QP_YAC_AV1,
+        QP_UDC_AV1,
+        QP_UAC_AV1,
+        QP_VDC_AV1,
+        QP_VAC_AV1,
+        QP_INDEX_YDC_AV1,
+        QP_INDEX_YAC_AV1,
+        QP_INDEX_UDC_AV1,
+        QP_INDEX_UAC_AV1,
+        QP_INDEX_VDC_AV1,
+        QP_INDEX_VAC_AV1,
+        QP_ARR_SIZE_AV1
+};
+
+#endif /* AVUTIL_QUANTIZATION_PARAMS_H */
-- 
2.22.0.709.g102302147b-goog



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