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Diffstat (limited to 'doc/examples/qsv_decode.c')
-rw-r--r-- | doc/examples/qsv_decode.c | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/doc/examples/qsv_decode.c b/doc/examples/qsv_decode.c new file mode 100644 index 0000000000..0cdef4466c --- /dev/null +++ b/doc/examples/qsv_decode.c @@ -0,0 +1,244 @@ +/* + * Copyright (c) 2015 Anton Khirnov + * + * 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 H.264 decoding example. + * + * @example qsv_decode.c + * This example shows how to do QSV-accelerated H.264 decoding with output + * frames in the GPU video surfaces. + */ + +#include "config.h" + +#include <stdio.h> + +#include "libavformat/avformat.h" +#include "libavformat/avio.h" + +#include "libavcodec/avcodec.h" + +#include "libavutil/buffer.h" +#include "libavutil/error.h" +#include "libavutil/hwcontext.h" +#include "libavutil/hwcontext_qsv.h" +#include "libavutil/mem.h" + +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 decode_packet(AVCodecContext *decoder_ctx, + AVFrame *frame, AVFrame *sw_frame, + AVPacket *pkt, AVIOContext *output_ctx) +{ + int ret = 0; + + ret = avcodec_send_packet(decoder_ctx, pkt); + if (ret < 0) { + fprintf(stderr, "Error during decoding\n"); + return ret; + } + + while (ret >= 0) { + int i, j; + + ret = avcodec_receive_frame(decoder_ctx, frame); + if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) + break; + else if (ret < 0) { + fprintf(stderr, "Error during decoding\n"); + return ret; + } + + /* A real program would do something useful with the decoded frame here. + * We just retrieve the raw data and write it to a file, which is rather + * useless but pedagogic. */ + ret = av_hwframe_transfer_data(sw_frame, frame, 0); + if (ret < 0) { + fprintf(stderr, "Error transferring the data to system memory\n"); + goto fail; + } + + for (i = 0; i < FF_ARRAY_ELEMS(sw_frame->data) && sw_frame->data[i]; i++) + for (j = 0; j < (sw_frame->height >> (i > 0)); j++) + avio_write(output_ctx, sw_frame->data[i] + j * sw_frame->linesize[i], sw_frame->width); + +fail: + av_frame_unref(sw_frame); + av_frame_unref(frame); + + if (ret < 0) + return ret; + } + + return 0; +} + +int main(int argc, char **argv) +{ + AVFormatContext *input_ctx = NULL; + AVStream *video_st = NULL; + AVCodecContext *decoder_ctx = NULL; + const AVCodec *decoder; + + AVPacket *pkt = NULL; + AVFrame *frame = NULL, *sw_frame = NULL; + + AVIOContext *output_ctx = NULL; + + int ret, i; + + AVBufferRef *device_ref = NULL; + + if (argc < 3) { + fprintf(stderr, "Usage: %s <input file> <output file>\n", argv[0]); + return 1; + } + + /* open the input file */ + ret = avformat_open_input(&input_ctx, argv[1], NULL, NULL); + if (ret < 0) { + fprintf(stderr, "Cannot open input file '%s': ", argv[1]); + goto finish; + } + + /* find the first H.264 video stream */ + for (i = 0; i < input_ctx->nb_streams; i++) { + AVStream *st = input_ctx->streams[i]; + + if (st->codecpar->codec_id == AV_CODEC_ID_H264 && !video_st) + video_st = st; + else + st->discard = AVDISCARD_ALL; + } + if (!video_st) { + fprintf(stderr, "No H.264 video stream in the input file\n"); + goto finish; + } + + /* open the hardware device */ + ret = av_hwdevice_ctx_create(&device_ref, AV_HWDEVICE_TYPE_QSV, + "auto", NULL, 0); + if (ret < 0) { + fprintf(stderr, "Cannot open the hardware device\n"); + goto finish; + } + + /* initialize the decoder */ + decoder = avcodec_find_decoder_by_name("h264_qsv"); + if (!decoder) { + fprintf(stderr, "The QSV decoder is not present in libavcodec\n"); + goto finish; + } + + decoder_ctx = avcodec_alloc_context3(decoder); + if (!decoder_ctx) { + ret = AVERROR(ENOMEM); + goto finish; + } + decoder_ctx->codec_id = AV_CODEC_ID_H264; + if (video_st->codecpar->extradata_size) { + decoder_ctx->extradata = av_mallocz(video_st->codecpar->extradata_size + + AV_INPUT_BUFFER_PADDING_SIZE); + if (!decoder_ctx->extradata) { + ret = AVERROR(ENOMEM); + goto finish; + } + memcpy(decoder_ctx->extradata, video_st->codecpar->extradata, + video_st->codecpar->extradata_size); + decoder_ctx->extradata_size = video_st->codecpar->extradata_size; + } + + + decoder_ctx->hw_device_ctx = av_buffer_ref(device_ref); + decoder_ctx->get_format = get_format; + + ret = avcodec_open2(decoder_ctx, NULL, NULL); + if (ret < 0) { + fprintf(stderr, "Error opening the decoder: "); + goto finish; + } + + /* open the output stream */ + ret = avio_open(&output_ctx, argv[2], AVIO_FLAG_WRITE); + if (ret < 0) { + fprintf(stderr, "Error opening the output context: "); + goto finish; + } + + frame = av_frame_alloc(); + sw_frame = av_frame_alloc(); + pkt = av_packet_alloc(); + if (!frame || !sw_frame || !pkt) { + ret = AVERROR(ENOMEM); + goto finish; + } + + /* actual decoding */ + while (ret >= 0) { + ret = av_read_frame(input_ctx, pkt); + if (ret < 0) + break; + + if (pkt->stream_index == video_st->index) + ret = decode_packet(decoder_ctx, frame, sw_frame, pkt, output_ctx); + + av_packet_unref(pkt); + } + + /* flush the decoder */ + ret = decode_packet(decoder_ctx, frame, sw_frame, NULL, output_ctx); + +finish: + if (ret < 0) { + char buf[1024]; + av_strerror(ret, buf, sizeof(buf)); + fprintf(stderr, "%s\n", buf); + } + + avformat_close_input(&input_ctx); + + av_frame_free(&frame); + av_frame_free(&sw_frame); + av_packet_free(&pkt); + + avcodec_free_context(&decoder_ctx); + + av_buffer_unref(&device_ref); + + avio_close(output_ctx); + + return ret; +} |