doc/examples: Add qsv_transcode example

Add qsv_transcode example which shows how to use qsv to do hardware
accelerated transcoding, also show how to dynamically set encoding
parameters.

examples:
Normal usage:
qsv_transcode input.mp4 h264_qsv output.mp4 "g 60"

Dynamic setting usage:
qsv_transcode input.mp4 hevc_qsv output.mp4 "g 60 asyne_depth 1"
100 "g 120"
This command initializes codec with gop_size 60 and change it to
120 after 100 frames

Signed-off-by: Wenbin Chen <wenbin.chen@intel.com>
Signed-off-by: Haihao Xiang <haihao.xiang@intel.com>

3 files changed, 442 insertions, 0 deletions

diff --git a/doc/examples/.gitignore b/doc/examples/.gitignore
index 44960e1de7..d787afdd4c 100644
--- a/doc/examples/.gitignore
+++ b/doc/examples/.gitignore
@@ -22,3 +22,4 @@
 /transcoding
 /vaapi_encode
 /vaapi_transcode
+/qsv_transcode
diff --git a/doc/examples/Makefile b/doc/examples/Makefile
index 81bfd34d5d..f937fbefda 100644
--- a/doc/examples/Makefile
+++ b/doc/examples/Makefile
@@ -21,6 +21,7 @@ EXAMPLES-$(CONFIG_TRANSCODE_AAC_EXAMPLE)     += transcode_aac
 EXAMPLES-$(CONFIG_TRANSCODING_EXAMPLE)       += transcoding
 EXAMPLES-$(CONFIG_VAAPI_ENCODE_EXAMPLE)      += vaapi_encode
 EXAMPLES-$(CONFIG_VAAPI_TRANSCODE_EXAMPLE)   += vaapi_transcode
+EXAMPLES-$(CONFIG_QSV_TRANSCODE_EXAMPLE)     += qsv_transcode
 
 EXAMPLES       := $(EXAMPLES-yes:%=doc/examples/%$(PROGSSUF)$(EXESUF))
 EXAMPLES_G     := $(EXAMPLES-yes:%=doc/examples/%$(PROGSSUF)_g$(EXESUF))
diff --git a/doc/examples/qsv_transcode.c b/doc/examples/qsv_transcode.c
new file mode 100644
index 0000000000..9b37bbea9f
--- /dev/null
+++ b/doc/examples/qsv_transcode.c
@@ -0,0 +1,440 @@
+/*
+ * Quick Sync Video (video transcoding) transcode sample
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+/**
+ * @file
+ * Intel QSV-accelerated transcoding example.
+ *
+ * @example qsv_transcode.c
+ * This example shows how to do QSV-accelerated transcoding and how to
+ * dynamically change encoder's option.
+ * Usage: qsv_transcode input_stream codec output_stream initial option
+ *                      { frame_number new_option }
+ * e.g: - qsv_transcode input.mp4 h264_qsv output_h264.mp4 "g 60"
+ *      - qsv_transcode input.mp4 hevc_qsv output_hevc.mp4 "g 60 async_depth 1"
+ *                      100 "g 120"
+ *         (initialize codec with gop_size 60 and change it to 120 after 100
+ *          frames)
+ */
+
+#include <stdio.h>
+#include <errno.h>
+
+#include <libavutil/hwcontext.h>
+#include <libavcodec/avcodec.h>
+#include <libavformat/avformat.h>
+#include <libavutil/opt.h>
+
+static AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL;
+static AVBufferRef *hw_device_ctx = NULL;
+static AVCodecContext *decoder_ctx = NULL, *encoder_ctx = NULL;
+static int video_stream = -1;
+
+typedef struct DynamicSetting {
+    int frame_number;
+    char* optstr;
+} DynamicSetting;
+static DynamicSetting *dynamic_setting;
+static int setting_number;
+static int current_setting_number;
+
+static int str_to_dict(char* optstr, AVDictionary **opt)
+{
+    char *key, *value;
+    if (strlen(optstr) == 0)
+        return 0;
+    key = strtok(optstr, " ");
+    if (key == NULL)
+        return AVERROR(ENAVAIL);
+    value = strtok(NULL, " ");
+    if (value == NULL)
+        return AVERROR(ENAVAIL);
+    av_dict_set(opt, key, value, 0);
+    do {
+        key = strtok(NULL, " ");
+        if (key == NULL)
+            return 0;
+        value = strtok(NULL, " ");
+        if (value == NULL)
+            return AVERROR(ENAVAIL);
+        av_dict_set(opt, key, value, 0);
+    } while(key != NULL);
+    return 0;
+}
+
+static int dynamic_set_parameter(AVCodecContext *avctx)
+{
+    AVDictionary *opts = NULL;
+    int ret = 0;
+    static int frame_number = 0;
+    frame_number++;
+    if (current_setting_number < setting_number &&
+        frame_number == dynamic_setting[current_setting_number].frame_number) {
+        AVDictionaryEntry *e = NULL;
+        ret = str_to_dict(dynamic_setting[current_setting_number].optstr, &opts);
+        if (ret < 0) {
+            fprintf(stderr, "The dynamic parameter is wrong\n");
+            goto fail;
+        }
+        /* Set common option. The dictionary will be freed and replaced
+         * by a new one containing all options not found in common option list.
+         * Then this new dictionary is used to set private option. */
+        if ((ret = av_opt_set_dict(avctx, &opts)) < 0)
+            goto fail;
+        /* Set codec specific option */
+        if ((ret = av_opt_set_dict(avctx->priv_data, &opts)) < 0)
+            goto fail;
+        /* There is no "framerate" option in commom option list. Use "-r" to set
+         * framerate, which is compatible with ffmpeg commandline. The video is
+         * assumed to be average frame rate, so set time_base to 1/framerate. */
+        e = av_dict_get(opts, "r", NULL, 0);
+        if (e) {
+            avctx->framerate = av_d2q(atof(e->value), INT_MAX);
+            encoder_ctx->time_base = av_inv_q(encoder_ctx->framerate);
+        }
+    }
+fail:
+    av_dict_free(&opts);
+    return ret;
+}
+
+static int get_format(AVCodecContext *avctx, const enum AVPixelFormat *pix_fmts)
+{
+    while (*pix_fmts != AV_PIX_FMT_NONE) {
+        if (*pix_fmts == AV_PIX_FMT_QSV) {
+            return AV_PIX_FMT_QSV;
+        }
+
+        pix_fmts++;
+    }
+
+    fprintf(stderr, "The QSV pixel format not offered in get_format()\n");
+
+    return AV_PIX_FMT_NONE;
+}
+
+static int open_input_file(char *filename)
+{
+    int ret;
+    const AVCodec *decoder = NULL;
+    AVStream *video = NULL;
+
+    if ((ret = avformat_open_input(&ifmt_ctx, filename, NULL, NULL)) < 0) {
+        fprintf(stderr, "Cannot open input file '%s', Error code: %s\n",
+                filename, av_err2str(ret));
+        return ret;
+    }
+
+    if ((ret = avformat_find_stream_info(ifmt_ctx, NULL)) < 0) {
+        fprintf(stderr, "Cannot find input stream information. Error code: %s\n",
+                av_err2str(ret));
+        return ret;
+    }
+
+    ret = av_find_best_stream(ifmt_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, NULL, 0);
+    if (ret < 0) {
+        fprintf(stderr, "Cannot find a video stream in the input file. "
+                "Error code: %s\n", av_err2str(ret));
+        return ret;
+    }
+    video_stream = ret;
+    video = ifmt_ctx->streams[video_stream];
+
+    switch(video->codecpar->codec_id) {
+    case AV_CODEC_ID_H264:
+        decoder = avcodec_find_decoder_by_name("h264_qsv");
+        break;
+    case AV_CODEC_ID_HEVC:
+        decoder = avcodec_find_decoder_by_name("hevc_qsv");
+        break;
+    case AV_CODEC_ID_VP9:
+        decoder = avcodec_find_decoder_by_name("vp9_qsv");
+        break;
+    case AV_CODEC_ID_VP8:
+        decoder = avcodec_find_decoder_by_name("vp8_qsv");
+        break;
+    case AV_CODEC_ID_AV1:
+        decoder = avcodec_find_decoder_by_name("av1_qsv");
+        break;
+    case AV_CODEC_ID_MPEG2VIDEO:
+        decoder = avcodec_find_decoder_by_name("mpeg2_qsv");
+        break;
+    case AV_CODEC_ID_MJPEG:
+        decoder = avcodec_find_decoder_by_name("mjpeg_qsv");
+        break;
+    default:
+        fprintf(stderr, "Codec is not supportted by qsv\n");
+        return AVERROR(ENAVAIL);
+    }
+
+    if (!(decoder_ctx = avcodec_alloc_context3(decoder)))
+        return AVERROR(ENOMEM);
+
+    if ((ret = avcodec_parameters_to_context(decoder_ctx, video->codecpar)) < 0) {
+        fprintf(stderr, "avcodec_parameters_to_context error. Error code: %s\n",
+                av_err2str(ret));
+        return ret;
+    }
+    decoder_ctx->framerate = av_guess_frame_rate(ifmt_ctx, video, NULL);
+
+    decoder_ctx->hw_device_ctx = av_buffer_ref(hw_device_ctx);
+    if (!decoder_ctx->hw_device_ctx) {
+        fprintf(stderr, "A hardware device reference create failed.\n");
+        return AVERROR(ENOMEM);
+    }
+    decoder_ctx->get_format    = get_format;
+    decoder_ctx->pkt_timebase = video->time_base;
+    if ((ret = avcodec_open2(decoder_ctx, decoder, NULL)) < 0)
+        fprintf(stderr, "Failed to open codec for decoding. Error code: %s\n",
+                av_err2str(ret));
+
+    return ret;
+}
+
+static int encode_write(AVPacket *enc_pkt, AVFrame *frame)
+{
+    int ret = 0;
+
+    av_packet_unref(enc_pkt);
+
+    if((ret = dynamic_set_parameter(encoder_ctx)) < 0) {
+        fprintf(stderr, "Failed to set dynamic parameter. Error code: %s\n",
+                av_err2str(ret));
+        goto end;
+    }
+
+    if ((ret = avcodec_send_frame(encoder_ctx, frame)) < 0) {
+        fprintf(stderr, "Error during encoding. Error code: %s\n", av_err2str(ret));
+        goto end;
+    }
+    while (1) {
+        if (ret = avcodec_receive_packet(encoder_ctx, enc_pkt))
+            break;
+        enc_pkt->stream_index = 0;
+        av_packet_rescale_ts(enc_pkt, encoder_ctx->time_base,
+                             ofmt_ctx->streams[0]->time_base);
+        if ((ret = av_interleaved_write_frame(ofmt_ctx, enc_pkt)) < 0) {
+            fprintf(stderr, "Error during writing data to output file. "
+                    "Error code: %s\n", av_err2str(ret));
+            return ret;
+        }
+    }
+
+end:
+    if (ret == AVERROR_EOF)
+        return 0;
+    ret = ((ret == AVERROR(EAGAIN)) ? 0:-1);
+    return ret;
+}
+
+static int dec_enc(AVPacket *pkt, const AVCodec *enc_codec, char *optstr)
+{
+    AVFrame *frame;
+    int ret = 0;
+
+    ret = avcodec_send_packet(decoder_ctx, pkt);
+    if (ret < 0) {
+        fprintf(stderr, "Error during decoding. Error code: %s\n", av_err2str(ret));
+        return ret;
+    }
+
+    while (ret >= 0) {
+        if (!(frame = av_frame_alloc()))
+            return AVERROR(ENOMEM);
+
+        ret = avcodec_receive_frame(decoder_ctx, frame);
+        if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
+            av_frame_free(&frame);
+            return 0;
+        } else if (ret < 0) {
+            fprintf(stderr, "Error while decoding. Error code: %s\n", av_err2str(ret));
+            goto fail;
+        }
+        if (!encoder_ctx->hw_frames_ctx) {
+            AVDictionaryEntry *e = NULL;
+            AVDictionary *opts = NULL;
+            AVStream *ost;
+            /* we need to ref hw_frames_ctx of decoder to initialize encoder's codec.
+               Only after we get a decoded frame, can we obtain its hw_frames_ctx */
+            encoder_ctx->hw_frames_ctx = av_buffer_ref(decoder_ctx->hw_frames_ctx);
+            if (!encoder_ctx->hw_frames_ctx) {
+                ret = AVERROR(ENOMEM);
+                goto fail;
+            }
+            /* set AVCodecContext Parameters for encoder, here we keep them stay
+             * the same as decoder.
+             */
+            encoder_ctx->time_base = av_inv_q(decoder_ctx->framerate);
+            encoder_ctx->pix_fmt   = AV_PIX_FMT_QSV;
+            encoder_ctx->width     = decoder_ctx->width;
+            encoder_ctx->height    = decoder_ctx->height;
+            if ((ret = str_to_dict(optstr, &opts)) < 0) {
+                fprintf(stderr, "Failed to set encoding parameter.\n");
+                goto fail;
+            }
+            /* There is no "framerate" option in commom option list. Use "-r" to
+            * set framerate, which is compatible with ffmpeg commandline. The
+            * video is assumed to be average frame rate, so set time_base to
+            * 1/framerate. */
+            e = av_dict_get(opts, "r", NULL, 0);
+            if (e) {
+                encoder_ctx->framerate = av_d2q(atof(e->value), INT_MAX);
+                encoder_ctx->time_base = av_inv_q(encoder_ctx->framerate);
+            }
+            if ((ret = avcodec_open2(encoder_ctx, enc_codec, &opts)) < 0) {
+                fprintf(stderr, "Failed to open encode codec. Error code: %s\n",
+                        av_err2str(ret));
+                av_dict_free(&opts);
+                goto fail;
+            }
+            av_dict_free(&opts);
+
+            if (!(ost = avformat_new_stream(ofmt_ctx, enc_codec))) {
+                fprintf(stderr, "Failed to allocate stream for output format.\n");
+                ret = AVERROR(ENOMEM);
+                goto fail;
+            }
+
+            ost->time_base = encoder_ctx->time_base;
+            ret = avcodec_parameters_from_context(ost->codecpar, encoder_ctx);
+            if (ret < 0) {
+                fprintf(stderr, "Failed to copy the stream parameters. "
+                        "Error code: %s\n", av_err2str(ret));
+                goto fail;
+            }
+
+            /* write the stream header */
+            if ((ret = avformat_write_header(ofmt_ctx, NULL)) < 0) {
+                fprintf(stderr, "Error while writing stream header. "
+                        "Error code: %s\n", av_err2str(ret));
+                goto fail;
+            }
+        }
+        frame->pts = av_rescale_q(frame->pts, decoder_ctx->pkt_timebase,
+                                  encoder_ctx->time_base);
+        if ((ret = encode_write(pkt, frame)) < 0)
+            fprintf(stderr, "Error during encoding and writing.\n");
+
+fail:
+        av_frame_free(&frame);
+        if (ret < 0)
+            return ret;
+    }
+    return 0;
+}
+
+int main(int argc, char **argv)
+{
+    const AVCodec *enc_codec;
+    int ret = 0;
+    AVPacket *dec_pkt;
+
+    if (argc < 5 || (argc - 5) % 2) {
+        av_log(NULL, AV_LOG_ERROR, "Usage: %s <input file> <encoder> <output file>"
+               " <\"encoding option set 0\"> [<frame_number> <\"encoding options set 1\">]...\n", argv[0]);
+        return 1;
+    }
+    setting_number = (argc - 5) / 2;
+    dynamic_setting = av_malloc(setting_number * sizeof(*dynamic_setting));
+    current_setting_number = 0;
+    for (int i = 0; i < setting_number; i++) {
+        dynamic_setting[i].frame_number = atoi(argv[i*2 + 5]);
+        dynamic_setting[i].optstr = argv[i*2 + 6];
+    }
+
+    ret = av_hwdevice_ctx_create(&hw_device_ctx, AV_HWDEVICE_TYPE_QSV, NULL, NULL, 0);
+    if (ret < 0) {
+        fprintf(stderr, "Failed to create a QSV device. Error code: %s\n", av_err2str(ret));
+        goto end;
+    }
+
+    dec_pkt = av_packet_alloc();
+    if (!dec_pkt) {
+        fprintf(stderr, "Failed to allocate decode packet\n");
+        goto end;
+    }
+
+    if ((ret = open_input_file(argv[1])) < 0)
+        goto end;
+
+    if (!(enc_codec = avcodec_find_encoder_by_name(argv[2]))) {
+        fprintf(stderr, "Could not find encoder '%s'\n", argv[2]);
+        ret = -1;
+        goto end;
+    }
+
+    if ((ret = (avformat_alloc_output_context2(&ofmt_ctx, NULL, NULL, argv[3]))) < 0) {
+        fprintf(stderr, "Failed to deduce output format from file extension. Error code: "
+                "%s\n", av_err2str(ret));
+        goto end;
+    }
+
+    if (!(encoder_ctx = avcodec_alloc_context3(enc_codec))) {
+        ret = AVERROR(ENOMEM);
+        goto end;
+    }
+
+    ret = avio_open(&ofmt_ctx->pb, argv[3], AVIO_FLAG_WRITE);
+    if (ret < 0) {
+        fprintf(stderr, "Cannot open output file. "
+                "Error code: %s\n", av_err2str(ret));
+        goto end;
+    }
+
+    /* read all packets and only transcoding video */
+    while (ret >= 0) {
+        if ((ret = av_read_frame(ifmt_ctx, dec_pkt)) < 0)
+            break;
+
+        if (video_stream == dec_pkt->stream_index)
+            ret = dec_enc(dec_pkt, enc_codec, argv[4]);
+
+        av_packet_unref(dec_pkt);
+    }
+
+    /* flush decoder */
+    av_packet_unref(dec_pkt);
+    if ((ret = dec_enc(dec_pkt, enc_codec, argv[4])) < 0) {
+        fprintf(stderr, "Failed to flush decoder %s\n", av_err2str(ret));
+        goto end;
+    }
+
+    /* flush encoder */
+    if ((ret = encode_write(dec_pkt, NULL)) < 0) {
+        fprintf(stderr, "Failed to flush encoder %s\n", av_err2str(ret));
+        goto end;
+    }
+
+    /* write the trailer for output stream */
+    if ((ret = av_write_trailer(ofmt_ctx)) < 0)
+        fprintf(stderr, "Failed to write trailer %s\n", av_err2str(ret));
+
+end:
+    avformat_close_input(&ifmt_ctx);
+    avformat_close_input(&ofmt_ctx);
+    avcodec_free_context(&decoder_ctx);
+    avcodec_free_context(&encoder_ctx);
+    av_buffer_unref(&hw_device_ctx);
+    av_packet_free(&dec_pkt);
+    av_freep(&dynamic_setting);
+    return ret;
+}