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

Juan De León juandl at google.com
Tue Jul 30 22:37:42 EEST 2019


av_get_qp_type_string now returns const char
added descriptions to QP in enum
Tell me what you think.

design doc: https://docs.google.com/document/d/1WClt3EqhjwdGXhEw386O0wfn3IBQ1Ib-_5emVM1gbnA/edit?usp=sharing

Signed-off-by: Juan De León <juandl at google.com>
---
 libavutil/Makefile              |   2 +
 libavutil/frame.h               |   6 ++
 libavutil/quantization_params.c |  41 ++++++++++++
 libavutil/quantization_params.h | 115 ++++++++++++++++++++++++++++++++
 4 files changed, 164 insertions(+)
 create mode 100644 libavutil/quantization_params.c
 create mode 100644 libavutil/quantization_params.h

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..b64fd9c02c 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 is stored as AVQuantizationParamsArray type, described in
+     * libavuitl/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..7d8b0a4526
--- /dev/null
+++ b/libavutil/quantization_params.c
@@ -0,0 +1,41 @@
+/*
+ * 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"
+
+static const char* const QP_NAMES_H264[] = {"qp", "qpcb", "qpcr"};
+
+static const char* const QP_NAMES_VP9[] = {"qyac", "qydc", "quvdc", "quvac",
+                                           "qiyac", "qiydc", "qiuvdc", "qiuvac"};
+
+static const char* const QP_NAMES_AV1[] = {"qyac", "qydc", "qudc", "quac", "qvdc", "qvac",
+                                      "qiyac", "qiydc", "qiudc", "qiuac", "qivdc", "qivac"};
+
+const char* av_get_qp_type_string(enum AVExtractQPSupportedCodecs codec_id, int index)
+{
+    switch (codec_id) {
+        case AV_EXTRACT_QP_CODEC_ID_H264:
+            return index < AV_QP_ARR_SIZE_H264 ? QP_NAMES_H264[index] :NULL;
+        case AV_EXTRACT_QP_CODEC_ID_VP9:
+            return index < AV_QP_ARR_SIZE_VP9  ? QP_NAMES_VP9[index]  :NULL;
+        case AV_EXTRACT_QP_CODEC_ID_AV1:
+            return index < AV_QP_ARR_SIZE_AV1  ? QP_NAMES_AV1[index]  :NULL;
+        default:
+            return NULL;
+    }
+}
diff --git a/libavutil/quantization_params.h b/libavutil/quantization_params.h
new file mode 100644
index 0000000000..561216ccbd
--- /dev/null
+++ b/libavutil/quantization_params.h
@@ -0,0 +1,115 @@
+/*
+ * 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
+
+/*
+ * Supported decoders for extraction and filter
+ */
+enum AVExtractQPSupportedCodecs {
+    AV_EXTRACT_QP_CODEC_ID_H264 = 0,
+    AV_EXTRACT_QP_CODEC_ID_VP9,
+    AV_EXTRACT_QP_CODEC_ID_AV1,
+};
+
+/**
+ * Enums for different codecs to store qp in the type array
+ * Each enum must have an array of strings describing each field
+ * declared in quantization_params.c
+ */
+
+enum AVQPArrIndexesH264 {
+    AV_QP_Y_H264 = 0,      // QPy
+    AV_QP_U_H264,          // QPcb
+    AV_QP_V_H264,          // QPcr
+    AV_QP_ARR_SIZE_H264
+};
+
+enum AVQPArrIndexesVP9 {
+    AV_QP_YAC_VP9 = 0,     // get_dc_quant[][base_q_idx] - in spec
+    AV_QP_YDC_VP9,         // get_dc_quant[][base_q_idx+delta_q_y_dc]
+    AV_QP_UVDC_VP9,        // get_dc_quant[][base_q_idx+delta_q_uv_dc]
+    AV_QP_UVAC_VP9,        // get_ac_quant[][base_q_idx+delta_q_uv_ac]
+    AV_QP_INDEX_YAC_VP9,   // base_q_idx
+    AV_QP_INDEX_YDC_VP9,   // base_q_idx+delta_q_y_dc
+    AV_QP_INDEX_UVDC_VP9,  // base_q_idx+delta_q_uv_dc
+    AV_QP_INDEX_UVAC_VP9,  // base_q_idx+delta_q_uv_ac
+    AV_QP_ARR_SIZE_VP9
+};
+
+enum AVQPArrIndexesAV1 {
+    AV_QP_YAC_AV1 = 0,    // dc_q(base_q_idx) - in spec
+    AV_QP_YDC_AV1,        // dc_q(base_q_idx+DeltaQYDc)
+    AV_QP_UDC_AV1,        // dc_q(base_q_idx+DeltaQUDc)
+    AV_QP_UAC_AV1,        // dc_q(base_q_idx+DeltaQUAc)
+    AV_QP_VDC_AV1,        // dc_q(base_q_idx+DeltaQVDc)
+    AV_QP_VAC_AV1,        // dc_q(base_q_idx+DeltaQVAc)
+    AV_QP_INDEX_YAC_AV1,  // base_q_idx
+    AV_QP_INDEX_YDC_AV1,  // base_q_idx+DeltaQYDc
+    AV_QP_INDEX_UDC_AV1,  // base_q_idx+DeltaQUDc
+    AV_QP_INDEX_UAC_AV1,  // base_q_idx+DeltaQUAc
+    AV_QP_INDEX_VDC_AV1,  // base_q_idx+DeltaQVDc
+    AV_QP_INDEX_VAC_AV1,  // base_q_idx+DeltaQVAc
+    AV_QP_ARR_SIZE_AV1
+};
+
+/**
+ * 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
+     */
+    int qp_type[AV_QP_ARR_SIZE_AV1];
+} AVQuantizationParams;
+
+/**
+ * For storing an array of AVQuantization parameters and its size
+ * Used as AVFrameSideData
+ */
+typedef struct AVQuantizationParamsArray {
+    /**
+     * Array of AVQuantizationParams type blocks
+     */
+    AVQuantizationParams *qp_block_array;
+    /**
+     * size of the array
+     */
+    int nb_blocks;
+    /**
+     * Stores an id corresponding to one of the suppported codecs
+     */
+    enum AVExtractQPSupportedCodecs codec_id;
+} AVQuantizationParamsArray;
+
+/**
+ * Get the string describing the qp type for the given codec
+ */
+const char* av_get_qp_type_string(enum AVExtractQPSupportedCodecs codec_id, int index);
+
+#endif /* AVUTIL_QUANTIZATION_PARAMS_H */
-- 
2.22.0.709.g102302147b-goog



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