[deb_ffmpeg.git] / ffmpeg / doc / examples / transcoding.c

/*
 * Copyright (c) 2010 Nicolas George
 * Copyright (c) 2011 Stefano Sabatini
 * Copyright (c) 2014 Andrey Utkin
 *
 * 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
 * API example for demuxing, decoding, filtering, encoding and muxing
 * @example transcoding.c
 */

#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libavfilter/avfiltergraph.h>
#include <libavfilter/avcodec.h>
#include <libavfilter/buffersink.h>
#include <libavfilter/buffersrc.h>
#include <libavutil/opt.h>
#include <libavutil/pixdesc.h>

static AVFormatContext *ifmt_ctx;
static AVFormatContext *ofmt_ctx;
typedef struct FilteringContext {
    AVFilterContext *buffersink_ctx;
    AVFilterContext *buffersrc_ctx;
    AVFilterGraph *filter_graph;
} FilteringContext;
static FilteringContext *filter_ctx;

static int open_input_file(const char *filename)
{
    int ret;
    unsigned int i;

    ifmt_ctx = NULL;
    if ((ret = avformat_open_input(&ifmt_ctx, filename, NULL, NULL)) < 0) {
        av_log(NULL, AV_LOG_ERROR, "Cannot open input file\n");
        return ret;
    }

    if ((ret = avformat_find_stream_info(ifmt_ctx, NULL)) < 0) {
        av_log(NULL, AV_LOG_ERROR, "Cannot find stream information\n");
        return ret;
    }

    for (i = 0; i < ifmt_ctx->nb_streams; i++) {
        AVStream *stream;
        AVCodecContext *codec_ctx;
        stream = ifmt_ctx->streams[i];
        codec_ctx = stream->codec;
        /* Reencode video & audio and remux subtitles etc. */
        if (codec_ctx->codec_type == AVMEDIA_TYPE_VIDEO
                || codec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
            /* Open decoder */
            ret = avcodec_open2(codec_ctx,
                    avcodec_find_decoder(codec_ctx->codec_id), NULL);
            if (ret < 0) {
                av_log(NULL, AV_LOG_ERROR, "Failed to open decoder for stream #%u\n", i);
                return ret;
            }
        }
    }

    av_dump_format(ifmt_ctx, 0, filename, 0);
    return 0;
}

static int open_output_file(const char *filename)
{
    AVStream *out_stream;
    AVStream *in_stream;
    AVCodecContext *dec_ctx, *enc_ctx;
    AVCodec *encoder;
    int ret;
    unsigned int i;

    ofmt_ctx = NULL;
    avformat_alloc_output_context2(&ofmt_ctx, NULL, NULL, filename);
    if (!ofmt_ctx) {
        av_log(NULL, AV_LOG_ERROR, "Could not create output context\n");
        return AVERROR_UNKNOWN;
    }


    for (i = 0; i < ifmt_ctx->nb_streams; i++) {
        out_stream = avformat_new_stream(ofmt_ctx, NULL);
        if (!out_stream) {
            av_log(NULL, AV_LOG_ERROR, "Failed allocating output stream\n");
            return AVERROR_UNKNOWN;
        }

        in_stream = ifmt_ctx->streams[i];
        dec_ctx = in_stream->codec;
        enc_ctx = out_stream->codec;

        if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO
                || dec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
            /* in this example, we choose transcoding to same codec */
            encoder = avcodec_find_encoder(dec_ctx->codec_id);
            if (!encoder) {
                av_log(NULL, AV_LOG_FATAL, "Neccessary encoder not found\n");
                return AVERROR_INVALIDDATA;
            }

            /* In this example, we transcode to same properties (picture size,
             * sample rate etc.). These properties can be changed for output
             * streams easily using filters */
            if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO) {
                enc_ctx->height = dec_ctx->height;
                enc_ctx->width = dec_ctx->width;
                enc_ctx->sample_aspect_ratio = dec_ctx->sample_aspect_ratio;
                /* take first format from list of supported formats */
                enc_ctx->pix_fmt = encoder->pix_fmts[0];
                /* video time_base can be set to whatever is handy and supported by encoder */
                enc_ctx->time_base = dec_ctx->time_base;
            } else {
                enc_ctx->sample_rate = dec_ctx->sample_rate;
                enc_ctx->channel_layout = dec_ctx->channel_layout;
                enc_ctx->channels = av_get_channel_layout_nb_channels(enc_ctx->channel_layout);
                /* take first format from list of supported formats */
                enc_ctx->sample_fmt = encoder->sample_fmts[0];
                enc_ctx->time_base = (AVRational){1, enc_ctx->sample_rate};
            }

            /* Third parameter can be used to pass settings to encoder */
            ret = avcodec_open2(enc_ctx, encoder, NULL);
            if (ret < 0) {
                av_log(NULL, AV_LOG_ERROR, "Cannot open video encoder for stream #%u\n", i);
                return ret;
            }
        } else if (dec_ctx->codec_type == AVMEDIA_TYPE_UNKNOWN) {
            av_log(NULL, AV_LOG_FATAL, "Elementary stream #%d is of unknown type, cannot proceed\n", i);
            return AVERROR_INVALIDDATA;
        } else {
            /* if this stream must be remuxed */
            ret = avcodec_copy_context(ofmt_ctx->streams[i]->codec,
                    ifmt_ctx->streams[i]->codec);
            if (ret < 0) {
                av_log(NULL, AV_LOG_ERROR, "Copying stream context failed\n");
                return ret;
            }
        }

        if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
            enc_ctx->flags |= CODEC_FLAG_GLOBAL_HEADER;

    }
    av_dump_format(ofmt_ctx, 0, filename, 1);

    if (!(ofmt_ctx->oformat->flags & AVFMT_NOFILE)) {
        ret = avio_open(&ofmt_ctx->pb, filename, AVIO_FLAG_WRITE);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Could not open output file '%s'", filename);
            return ret;
        }
    }

    /* init muxer, write output file header */
    ret = avformat_write_header(ofmt_ctx, NULL);
    if (ret < 0) {
        av_log(NULL, AV_LOG_ERROR, "Error occurred when opening output file\n");
        return ret;
    }

    return 0;
}

static int init_filter(FilteringContext* fctx, AVCodecContext *dec_ctx,
        AVCodecContext *enc_ctx, const char *filter_spec)
{
    char args[512];
    int ret = 0;
    AVFilter *buffersrc = NULL;
    AVFilter *buffersink = NULL;
    AVFilterContext *buffersrc_ctx = NULL;
    AVFilterContext *buffersink_ctx = NULL;
    AVFilterInOut *outputs = avfilter_inout_alloc();
    AVFilterInOut *inputs  = avfilter_inout_alloc();
    AVFilterGraph *filter_graph = avfilter_graph_alloc();

    if (!outputs || !inputs || !filter_graph) {
        ret = AVERROR(ENOMEM);
        goto end;
    }

    if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO) {
        buffersrc = avfilter_get_by_name("buffer");
        buffersink = avfilter_get_by_name("buffersink");
        if (!buffersrc || !buffersink) {
            av_log(NULL, AV_LOG_ERROR, "filtering source or sink element not found\n");
            ret = AVERROR_UNKNOWN;
            goto end;
        }

        snprintf(args, sizeof(args),
                "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
                dec_ctx->width, dec_ctx->height, dec_ctx->pix_fmt,
                dec_ctx->time_base.num, dec_ctx->time_base.den,
                dec_ctx->sample_aspect_ratio.num,
                dec_ctx->sample_aspect_ratio.den);

        ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
                args, NULL, filter_graph);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot create buffer source\n");
            goto end;
        }

        ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
                NULL, NULL, filter_graph);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot create buffer sink\n");
            goto end;
        }

        ret = av_opt_set_bin(buffersink_ctx, "pix_fmts",
                (uint8_t*)&enc_ctx->pix_fmt, sizeof(enc_ctx->pix_fmt),
                AV_OPT_SEARCH_CHILDREN);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot set output pixel format\n");
            goto end;
        }
    } else if (dec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
        buffersrc = avfilter_get_by_name("abuffer");
        buffersink = avfilter_get_by_name("abuffersink");
        if (!buffersrc || !buffersink) {
            av_log(NULL, AV_LOG_ERROR, "filtering source or sink element not found\n");
            ret = AVERROR_UNKNOWN;
            goto end;
        }

        if (!dec_ctx->channel_layout)
            dec_ctx->channel_layout =
                av_get_default_channel_layout(dec_ctx->channels);
        snprintf(args, sizeof(args),
                "time_base=%d/%d:sample_rate=%d:sample_fmt=%s:channel_layout=0x%"PRIx64,
                dec_ctx->time_base.num, dec_ctx->time_base.den, dec_ctx->sample_rate,
                av_get_sample_fmt_name(dec_ctx->sample_fmt),
                dec_ctx->channel_layout);
        ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
                args, NULL, filter_graph);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer source\n");
            goto end;
        }

        ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
                NULL, NULL, filter_graph);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer sink\n");
            goto end;
        }

        ret = av_opt_set_bin(buffersink_ctx, "sample_fmts",
                (uint8_t*)&enc_ctx->sample_fmt, sizeof(enc_ctx->sample_fmt),
                AV_OPT_SEARCH_CHILDREN);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot set output sample format\n");
            goto end;
        }

        ret = av_opt_set_bin(buffersink_ctx, "channel_layouts",
                (uint8_t*)&enc_ctx->channel_layout,
                sizeof(enc_ctx->channel_layout), AV_OPT_SEARCH_CHILDREN);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot set output channel layout\n");
            goto end;
        }

        ret = av_opt_set_bin(buffersink_ctx, "sample_rates",
                (uint8_t*)&enc_ctx->sample_rate, sizeof(enc_ctx->sample_rate),
                AV_OPT_SEARCH_CHILDREN);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Cannot set output sample rate\n");
            goto end;
        }
    } else {
        ret = AVERROR_UNKNOWN;
        goto end;
    }

    /* Endpoints for the filter graph. */
    outputs->name       = av_strdup("in");
    outputs->filter_ctx = buffersrc_ctx;
    outputs->pad_idx    = 0;
    outputs->next       = NULL;

    inputs->name       = av_strdup("out");
    inputs->filter_ctx = buffersink_ctx;
    inputs->pad_idx    = 0;
    inputs->next       = NULL;

    if (!outputs->name || !inputs->name) {
        ret = AVERROR(ENOMEM);
        goto end;
    }

    if ((ret = avfilter_graph_parse_ptr(filter_graph, filter_spec,
                    &inputs, &outputs, NULL)) < 0)
        goto end;

    if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0)
        goto end;

    /* Fill FilteringContext */
    fctx->buffersrc_ctx = buffersrc_ctx;
    fctx->buffersink_ctx = buffersink_ctx;
    fctx->filter_graph = filter_graph;

end:
    avfilter_inout_free(&inputs);
    avfilter_inout_free(&outputs);

    return ret;
}

static int init_filters(void)
{
    const char *filter_spec;
    unsigned int i;
    int ret;
    filter_ctx = av_malloc_array(ifmt_ctx->nb_streams, sizeof(*filter_ctx));
    if (!filter_ctx)
        return AVERROR(ENOMEM);

    for (i = 0; i < ifmt_ctx->nb_streams; i++) {
        filter_ctx[i].buffersrc_ctx  = NULL;
        filter_ctx[i].buffersink_ctx = NULL;
        filter_ctx[i].filter_graph   = NULL;
        if (!(ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO
                || ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO))
            continue;


        if (ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
            filter_spec = "null"; /* passthrough (dummy) filter for video */
        else
            filter_spec = "anull"; /* passthrough (dummy) filter for audio */
        ret = init_filter(&filter_ctx[i], ifmt_ctx->streams[i]->codec,
                ofmt_ctx->streams[i]->codec, filter_spec);
        if (ret)
            return ret;
    }
    return 0;
}

static int encode_write_frame(AVFrame *filt_frame, unsigned int stream_index, int *got_frame) {
    int ret;
    int got_frame_local;
    AVPacket enc_pkt;
    int (*enc_func)(AVCodecContext *, AVPacket *, const AVFrame *, int *) =
        (ifmt_ctx->streams[stream_index]->codec->codec_type ==
         AVMEDIA_TYPE_VIDEO) ? avcodec_encode_video2 : avcodec_encode_audio2;

    if (!got_frame)
        got_frame = &got_frame_local;

    av_log(NULL, AV_LOG_INFO, "Encoding frame\n");
    /* encode filtered frame */
    enc_pkt.data = NULL;
    enc_pkt.size = 0;
    av_init_packet(&enc_pkt);
    ret = enc_func(ofmt_ctx->streams[stream_index]->codec, &enc_pkt,
            filt_frame, got_frame);
    av_frame_free(&filt_frame);
    if (ret < 0)
        return ret;
    if (!(*got_frame))
        return 0;

    /* prepare packet for muxing */
    enc_pkt.stream_index = stream_index;
    av_packet_rescale_ts(&enc_pkt,
                         ofmt_ctx->streams[stream_index]->codec->time_base,
                         ofmt_ctx->streams[stream_index]->time_base);

    av_log(NULL, AV_LOG_DEBUG, "Muxing frame\n");
    /* mux encoded frame */
    ret = av_interleaved_write_frame(ofmt_ctx, &enc_pkt);
    return ret;
}

static int filter_encode_write_frame(AVFrame *frame, unsigned int stream_index)
{
    int ret;
    AVFrame *filt_frame;

    av_log(NULL, AV_LOG_INFO, "Pushing decoded frame to filters\n");
    /* push the decoded frame into the filtergraph */
    ret = av_buffersrc_add_frame_flags(filter_ctx[stream_index].buffersrc_ctx,
            frame, 0);
    if (ret < 0) {
        av_log(NULL, AV_LOG_ERROR, "Error while feeding the filtergraph\n");
        return ret;
    }

    /* pull filtered frames from the filtergraph */
    while (1) {
        filt_frame = av_frame_alloc();
        if (!filt_frame) {
            ret = AVERROR(ENOMEM);
            break;
        }
        av_log(NULL, AV_LOG_INFO, "Pulling filtered frame from filters\n");
        ret = av_buffersink_get_frame(filter_ctx[stream_index].buffersink_ctx,
                filt_frame);
        if (ret < 0) {
            /* if no more frames for output - returns AVERROR(EAGAIN)
             * if flushed and no more frames for output - returns AVERROR_EOF
             * rewrite retcode to 0 to show it as normal procedure completion
             */
            if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
                ret = 0;
            av_frame_free(&filt_frame);
            break;
        }

        filt_frame->pict_type = AV_PICTURE_TYPE_NONE;
        ret = encode_write_frame(filt_frame, stream_index, NULL);
        if (ret < 0)
            break;
    }

    return ret;
}

static int flush_encoder(unsigned int stream_index)
{
    int ret;
    int got_frame;

    if (!(ofmt_ctx->streams[stream_index]->codec->codec->capabilities &
                CODEC_CAP_DELAY))
        return 0;

    while (1) {
        av_log(NULL, AV_LOG_INFO, "Flushing stream #%u encoder\n", stream_index);
        ret = encode_write_frame(NULL, stream_index, &got_frame);
        if (ret < 0)
            break;
        if (!got_frame)
            return 0;
    }
    return ret;
}

int main(int argc, char **argv)
{
    int ret;
    AVPacket packet = { .data = NULL, .size = 0 };
    AVFrame *frame = NULL;
    enum AVMediaType type;
    unsigned int stream_index;
    unsigned int i;
    int got_frame;
    int (*dec_func)(AVCodecContext *, AVFrame *, int *, const AVPacket *);

    if (argc != 3) {
        av_log(NULL, AV_LOG_ERROR, "Usage: %s <input file> <output file>\n", argv[0]);
        return 1;
    }

    av_register_all();
    avfilter_register_all();

    if ((ret = open_input_file(argv[1])) < 0)
        goto end;
    if ((ret = open_output_file(argv[2])) < 0)
        goto end;
    if ((ret = init_filters()) < 0)
        goto end;

    /* read all packets */
    while (1) {
        if ((ret = av_read_frame(ifmt_ctx, &packet)) < 0)
            break;
        stream_index = packet.stream_index;
        type = ifmt_ctx->streams[packet.stream_index]->codec->codec_type;
        av_log(NULL, AV_LOG_DEBUG, "Demuxer gave frame of stream_index %u\n",
                stream_index);

        if (filter_ctx[stream_index].filter_graph) {
            av_log(NULL, AV_LOG_DEBUG, "Going to reencode&filter the frame\n");
            frame = av_frame_alloc();
            if (!frame) {
                ret = AVERROR(ENOMEM);
                break;
            }
            av_packet_rescale_ts(&packet,
                                 ifmt_ctx->streams[stream_index]->time_base,
                                 ifmt_ctx->streams[stream_index]->codec->time_base);
            dec_func = (type == AVMEDIA_TYPE_VIDEO) ? avcodec_decode_video2 :
                avcodec_decode_audio4;
            ret = dec_func(ifmt_ctx->streams[stream_index]->codec, frame,
                    &got_frame, &packet);
            if (ret < 0) {
                av_frame_free(&frame);
                av_log(NULL, AV_LOG_ERROR, "Decoding failed\n");
                break;
            }

            if (got_frame) {
                frame->pts = av_frame_get_best_effort_timestamp(frame);
                ret = filter_encode_write_frame(frame, stream_index);
                av_frame_free(&frame);
                if (ret < 0)
                    goto end;
            } else {
                av_frame_free(&frame);
            }
        } else {
            /* remux this frame without reencoding */
            av_packet_rescale_ts(&packet,
                                 ifmt_ctx->streams[stream_index]->time_base,
                                 ofmt_ctx->streams[stream_index]->time_base);

            ret = av_interleaved_write_frame(ofmt_ctx, &packet);
            if (ret < 0)
                goto end;
        }
        av_free_packet(&packet);
    }

    /* flush filters and encoders */
    for (i = 0; i < ifmt_ctx->nb_streams; i++) {
        /* flush filter */
        if (!filter_ctx[i].filter_graph)
            continue;
        ret = filter_encode_write_frame(NULL, i);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Flushing filter failed\n");
            goto end;
        }

        /* flush encoder */
        ret = flush_encoder(i);
        if (ret < 0) {
            av_log(NULL, AV_LOG_ERROR, "Flushing encoder failed\n");
            goto end;
        }
    }

    av_write_trailer(ofmt_ctx);
end:
    av_free_packet(&packet);
    av_frame_free(&frame);
    for (i = 0; i < ifmt_ctx->nb_streams; i++) {
        avcodec_close(ifmt_ctx->streams[i]->codec);
        if (ofmt_ctx && ofmt_ctx->nb_streams > i && ofmt_ctx->streams[i] && ofmt_ctx->streams[i]->codec)
            avcodec_close(ofmt_ctx->streams[i]->codec);
        if (filter_ctx && filter_ctx[i].filter_graph)
            avfilter_graph_free(&filter_ctx[i].filter_graph);
    }
    av_free(filter_ctx);
    avformat_close_input(&ifmt_ctx);
    if (ofmt_ctx && !(ofmt_ctx->oformat->flags & AVFMT_NOFILE))
        avio_close(ofmt_ctx->pb);
    avformat_free_context(ofmt_ctx);

    if (ret < 0)
        av_log(NULL, AV_LOG_ERROR, "Error occurred: %s\n", av_err2str(ret));

    return ret ? 1 : 0;
}
Commit	Line	Data
2ba45a60 DM	1	/*
	2	* Copyright (c) 2010 Nicolas George
	3	* Copyright (c) 2011 Stefano Sabatini
	4	* Copyright (c) 2014 Andrey Utkin
	5	*
	6	* Permission is hereby granted, free of charge, to any person obtaining a copy
	7	* of this software and associated documentation files (the "Software"), to deal
	8	* in the Software without restriction, including without limitation the rights
	9	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	10	* copies of the Software, and to permit persons to whom the Software is
	11	* furnished to do so, subject to the following conditions:
	12	*
	13	* The above copyright notice and this permission notice shall be included in
	14	* all copies or substantial portions of the Software.
	15	*
	16	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	17	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	18	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	19	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	20	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	21	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	22	* THE SOFTWARE.
	23	*/
	24
	25	/**
	26	* @file
	27	* API example for demuxing, decoding, filtering, encoding and muxing
	28	* @example transcoding.c
	29	*/
	30
	31	#include <libavcodec/avcodec.h>
	32	#include <libavformat/avformat.h>
	33	#include <libavfilter/avfiltergraph.h>
	34	#include <libavfilter/avcodec.h>
	35	#include <libavfilter/buffersink.h>
	36	#include <libavfilter/buffersrc.h>
	37	#include <libavutil/opt.h>
	38	#include <libavutil/pixdesc.h>
	39
	40	static AVFormatContext *ifmt_ctx;
	41	static AVFormatContext *ofmt_ctx;
	42	typedef struct FilteringContext {
	43	AVFilterContext *buffersink_ctx;
	44	AVFilterContext *buffersrc_ctx;
	45	AVFilterGraph *filter_graph;
	46	} FilteringContext;
	47	static FilteringContext *filter_ctx;
	48
	49	static int open_input_file(const char *filename)
	50	{
	51	int ret;
	52	unsigned int i;
	53
	54	ifmt_ctx = NULL;
	55	if ((ret = avformat_open_input(&ifmt_ctx, filename, NULL, NULL)) < 0) {
	56	av_log(NULL, AV_LOG_ERROR, "Cannot open input file\n");
	57	return ret;
	58	}
	59
	60	if ((ret = avformat_find_stream_info(ifmt_ctx, NULL)) < 0) {
	61	av_log(NULL, AV_LOG_ERROR, "Cannot find stream information\n");
	62	return ret;
	63	}
	64
65	for (i = 0; i < ifmt_ctx->nb_streams; i++) {
66	AVStream *stream;
67	AVCodecContext *codec_ctx;
68	stream = ifmt_ctx->streams[i];
69	codec_ctx = stream->codec;
70	/* Reencode video & audio and remux subtitles etc. */
71	if (codec_ctx->codec_type == AVMEDIA_TYPE_VIDEO
72	\|\| codec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
73	/* Open decoder */
74	ret = avcodec_open2(codec_ctx,
75	avcodec_find_decoder(codec_ctx->codec_id), NULL);
76	if (ret < 0) {
77	av_log(NULL, AV_LOG_ERROR, "Failed to open decoder for stream #%u\n", i);
78	return ret;
79	}
80	}
81	}
82
83	av_dump_format(ifmt_ctx, 0, filename, 0);
84	return 0;
85	}
86
87	static int open_output_file(const char *filename)
88	{
89	AVStream *out_stream;
90	AVStream *in_stream;
91	AVCodecContext dec_ctx, enc_ctx;
92	AVCodec *encoder;
93	int ret;
94	unsigned int i;
95
96	ofmt_ctx = NULL;
97	avformat_alloc_output_context2(&ofmt_ctx, NULL, NULL, filename);
98	if (!ofmt_ctx) {
99	av_log(NULL, AV_LOG_ERROR, "Could not create output context\n");
100	return AVERROR_UNKNOWN;
101	}
102
103
104	for (i = 0; i < ifmt_ctx->nb_streams; i++) {
105	out_stream = avformat_new_stream(ofmt_ctx, NULL);
106	if (!out_stream) {
107	av_log(NULL, AV_LOG_ERROR, "Failed allocating output stream\n");
108	return AVERROR_UNKNOWN;
109	}
110
111	in_stream = ifmt_ctx->streams[i];
112	dec_ctx = in_stream->codec;
113	enc_ctx = out_stream->codec;
114
115	if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO
116	\|\| dec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
117	/* in this example, we choose transcoding to same codec */
118	encoder = avcodec_find_encoder(dec_ctx->codec_id);
dcebb6f3 DM	119	if (!encoder) {
	120	av_log(NULL, AV_LOG_FATAL, "Neccessary encoder not found\n");
	121	return AVERROR_INVALIDDATA;
	122	}
2ba45a60 DM	123
	124	/* In this example, we transcode to same properties (picture size,
	125	* sample rate etc.). These properties can be changed for output
	126	* streams easily using filters */
	127	if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO) {
	128	enc_ctx->height = dec_ctx->height;
	129	enc_ctx->width = dec_ctx->width;
	130	enc_ctx->sample_aspect_ratio = dec_ctx->sample_aspect_ratio;
	131	/* take first format from list of supported formats */
	132	enc_ctx->pix_fmt = encoder->pix_fmts[0];
	133	/* video time_base can be set to whatever is handy and supported by encoder */
	134	enc_ctx->time_base = dec_ctx->time_base;
	135	} else {
	136	enc_ctx->sample_rate = dec_ctx->sample_rate;
	137	enc_ctx->channel_layout = dec_ctx->channel_layout;
	138	enc_ctx->channels = av_get_channel_layout_nb_channels(enc_ctx->channel_layout);
	139	/* take first format from list of supported formats */
	140	enc_ctx->sample_fmt = encoder->sample_fmts[0];
	141	enc_ctx->time_base = (AVRational){1, enc_ctx->sample_rate};
	142	}
	143
	144	/* Third parameter can be used to pass settings to encoder */
	145	ret = avcodec_open2(enc_ctx, encoder, NULL);
	146	if (ret < 0) {
	147	av_log(NULL, AV_LOG_ERROR, "Cannot open video encoder for stream #%u\n", i);
	148	return ret;
	149	}
	150	} else if (dec_ctx->codec_type == AVMEDIA_TYPE_UNKNOWN) {
	151	av_log(NULL, AV_LOG_FATAL, "Elementary stream #%d is of unknown type, cannot proceed\n", i);
	152	return AVERROR_INVALIDDATA;
	153	} else {
	154	/* if this stream must be remuxed */
	155	ret = avcodec_copy_context(ofmt_ctx->streams[i]->codec,
	156	ifmt_ctx->streams[i]->codec);
	157	if (ret < 0) {
	158	av_log(NULL, AV_LOG_ERROR, "Copying stream context failed\n");
	159	return ret;
	160	}
	161	}
	162
	163	if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
	164	enc_ctx->flags \|= CODEC_FLAG_GLOBAL_HEADER;
	165
	166	}
	167	av_dump_format(ofmt_ctx, 0, filename, 1);
	168
	169	if (!(ofmt_ctx->oformat->flags & AVFMT_NOFILE)) {
	170	ret = avio_open(&ofmt_ctx->pb, filename, AVIO_FLAG_WRITE);
	171	if (ret < 0) {
	172	av_log(NULL, AV_LOG_ERROR, "Could not open output file '%s'", filename);
	173	return ret;
	174	}
	175	}
	176
	177	/* init muxer, write output file header */
	178	ret = avformat_write_header(ofmt_ctx, NULL);
	179	if (ret < 0) {
	180	av_log(NULL, AV_LOG_ERROR, "Error occurred when opening output file\n");
	181	return ret;
	182	}
	183
	184	return 0;
	185	}
	186
187	static int init_filter(FilteringContext* fctx, AVCodecContext *dec_ctx,
188	AVCodecContext enc_ctx, const char filter_spec)
189	{
190	char args[512];
191	int ret = 0;
192	AVFilter *buffersrc = NULL;
193	AVFilter *buffersink = NULL;
194	AVFilterContext *buffersrc_ctx = NULL;
195	AVFilterContext *buffersink_ctx = NULL;
196	AVFilterInOut *outputs = avfilter_inout_alloc();
197	AVFilterInOut *inputs = avfilter_inout_alloc();
198	AVFilterGraph *filter_graph = avfilter_graph_alloc();
199
200	if (!outputs \|\| !inputs \|\| !filter_graph) {
201	ret = AVERROR(ENOMEM);
202	goto end;
203	}
204
205	if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO) {
206	buffersrc = avfilter_get_by_name("buffer");
207	buffersink = avfilter_get_by_name("buffersink");
208	if (!buffersrc \|\| !buffersink) {
209	av_log(NULL, AV_LOG_ERROR, "filtering source or sink element not found\n");
210	ret = AVERROR_UNKNOWN;
211	goto end;
212	}
213
214	snprintf(args, sizeof(args),
215	"video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
216	dec_ctx->width, dec_ctx->height, dec_ctx->pix_fmt,
217	dec_ctx->time_base.num, dec_ctx->time_base.den,
218	dec_ctx->sample_aspect_ratio.num,
219	dec_ctx->sample_aspect_ratio.den);
220
221	ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
222	args, NULL, filter_graph);
223	if (ret < 0) {
224	av_log(NULL, AV_LOG_ERROR, "Cannot create buffer source\n");
225	goto end;
226	}
227
228	ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
229	NULL, NULL, filter_graph);
230	if (ret < 0) {
231	av_log(NULL, AV_LOG_ERROR, "Cannot create buffer sink\n");
232	goto end;
233	}
234
235	ret = av_opt_set_bin(buffersink_ctx, "pix_fmts",
236	(uint8_t*)&enc_ctx->pix_fmt, sizeof(enc_ctx->pix_fmt),
237	AV_OPT_SEARCH_CHILDREN);
238	if (ret < 0) {
239	av_log(NULL, AV_LOG_ERROR, "Cannot set output pixel format\n");
240	goto end;
241	}
242	} else if (dec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
243	buffersrc = avfilter_get_by_name("abuffer");
244	buffersink = avfilter_get_by_name("abuffersink");
245	if (!buffersrc \|\| !buffersink) {
246	av_log(NULL, AV_LOG_ERROR, "filtering source or sink element not found\n");
247	ret = AVERROR_UNKNOWN;
248	goto end;
249	}
250
251	if (!dec_ctx->channel_layout)
252	dec_ctx->channel_layout =
253	av_get_default_channel_layout(dec_ctx->channels);
254	snprintf(args, sizeof(args),
255	"time_base=%d/%d:sample_rate=%d:sample_fmt=%s:channel_layout=0x%"PRIx64,
256	dec_ctx->time_base.num, dec_ctx->time_base.den, dec_ctx->sample_rate,
257	av_get_sample_fmt_name(dec_ctx->sample_fmt),
258	dec_ctx->channel_layout);
259	ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
260	args, NULL, filter_graph);
261	if (ret < 0) {
262	av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer source\n");
263	goto end;
264	}
265
266	ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
267	NULL, NULL, filter_graph);
268	if (ret < 0) {
269	av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer sink\n");
270	goto end;
271	}
272
273	ret = av_opt_set_bin(buffersink_ctx, "sample_fmts",
274	(uint8_t*)&enc_ctx->sample_fmt, sizeof(enc_ctx->sample_fmt),
275	AV_OPT_SEARCH_CHILDREN);
276	if (ret < 0) {
277	av_log(NULL, AV_LOG_ERROR, "Cannot set output sample format\n");
278	goto end;
279	}
280
281	ret = av_opt_set_bin(buffersink_ctx, "channel_layouts",
282	(uint8_t*)&enc_ctx->channel_layout,
283	sizeof(enc_ctx->channel_layout), AV_OPT_SEARCH_CHILDREN);
284	if (ret < 0) {
285	av_log(NULL, AV_LOG_ERROR, "Cannot set output channel layout\n");
286	goto end;
287	}
288
289	ret = av_opt_set_bin(buffersink_ctx, "sample_rates",
290	(uint8_t*)&enc_ctx->sample_rate, sizeof(enc_ctx->sample_rate),
291	AV_OPT_SEARCH_CHILDREN);
292	if (ret < 0) {
293	av_log(NULL, AV_LOG_ERROR, "Cannot set output sample rate\n");
294	goto end;
295	}
296	} else {
297	ret = AVERROR_UNKNOWN;
298	goto end;
299	}
300
301	/* Endpoints for the filter graph. */
302	outputs->name = av_strdup("in");
303	outputs->filter_ctx = buffersrc_ctx;
304	outputs->pad_idx = 0;
305	outputs->next = NULL;
306
307	inputs->name = av_strdup("out");
308	inputs->filter_ctx = buffersink_ctx;
309	inputs->pad_idx = 0;
310	inputs->next = NULL;
311
312	if (!outputs->name \|\| !inputs->name) {
313	ret = AVERROR(ENOMEM);
314	goto end;
315	}
316
317	if ((ret = avfilter_graph_parse_ptr(filter_graph, filter_spec,
318	&inputs, &outputs, NULL)) < 0)
319	goto end;
320
321	if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0)
322	goto end;
323
324	/* Fill FilteringContext */
325	fctx->buffersrc_ctx = buffersrc_ctx;
326	fctx->buffersink_ctx = buffersink_ctx;
327	fctx->filter_graph = filter_graph;
328
329	end:
330	avfilter_inout_free(&inputs);
331	avfilter_inout_free(&outputs);
332
333	return ret;
334	}
335
336	static int init_filters(void)
337	{
338	const char *filter_spec;
339	unsigned int i;
340	int ret;
341	filter_ctx = av_malloc_array(ifmt_ctx->nb_streams, sizeof(*filter_ctx));
342	if (!filter_ctx)
343	return AVERROR(ENOMEM);
344
345	for (i = 0; i < ifmt_ctx->nb_streams; i++) {
346	filter_ctx[i].buffersrc_ctx = NULL;
347	filter_ctx[i].buffersink_ctx = NULL;
348	filter_ctx[i].filter_graph = NULL;
349	if (!(ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO
350	\|\| ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO))
351	continue;
352
353
354	if (ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
355	filter_spec = "null"; /* passthrough (dummy) filter for video */
356	else
357	filter_spec = "anull"; /* passthrough (dummy) filter for audio */
358	ret = init_filter(&filter_ctx[i], ifmt_ctx->streams[i]->codec,
359	ofmt_ctx->streams[i]->codec, filter_spec);
360	if (ret)
361	return ret;
362	}
363	return 0;
364	}
365
366	static int encode_write_frame(AVFrame filt_frame, unsigned int stream_index, int got_frame) {
367	int ret;
368	int got_frame_local;
369	AVPacket enc_pkt;
370	int (enc_func)(AVCodecContext , AVPacket , const AVFrame , int *) =
371	(ifmt_ctx->streams[stream_index]->codec->codec_type ==
372	AVMEDIA_TYPE_VIDEO) ? avcodec_encode_video2 : avcodec_encode_audio2;
373
374	if (!got_frame)
375	got_frame = &got_frame_local;
376
377	av_log(NULL, AV_LOG_INFO, "Encoding frame\n");
378	/* encode filtered frame */
379	enc_pkt.data = NULL;
380	enc_pkt.size = 0;
381	av_init_packet(&enc_pkt);
382	ret = enc_func(ofmt_ctx->streams[stream_index]->codec, &enc_pkt,
383	filt_frame, got_frame);
384	av_frame_free(&filt_frame);
385	if (ret < 0)
386	return ret;
387	if (!(*got_frame))
388	return 0;
389
390	/* prepare packet for muxing */
391	enc_pkt.stream_index = stream_index;
f6fa7814 DM	392	av_packet_rescale_ts(&enc_pkt,
	393	ofmt_ctx->streams[stream_index]->codec->time_base,
	394	ofmt_ctx->streams[stream_index]->time_base);
2ba45a60 DM	395
	396	av_log(NULL, AV_LOG_DEBUG, "Muxing frame\n");
	397	/* mux encoded frame */
	398	ret = av_interleaved_write_frame(ofmt_ctx, &enc_pkt);
	399	return ret;
	400	}
	401
	402	static int filter_encode_write_frame(AVFrame *frame, unsigned int stream_index)
	403	{
	404	int ret;
	405	AVFrame *filt_frame;
	406
	407	av_log(NULL, AV_LOG_INFO, "Pushing decoded frame to filters\n");
	408	/* push the decoded frame into the filtergraph */
	409	ret = av_buffersrc_add_frame_flags(filter_ctx[stream_index].buffersrc_ctx,
	410	frame, 0);
	411	if (ret < 0) {
	412	av_log(NULL, AV_LOG_ERROR, "Error while feeding the filtergraph\n");
	413	return ret;
	414	}
	415
	416	/* pull filtered frames from the filtergraph */
	417	while (1) {
	418	filt_frame = av_frame_alloc();
	419	if (!filt_frame) {
	420	ret = AVERROR(ENOMEM);
	421	break;
	422	}
	423	av_log(NULL, AV_LOG_INFO, "Pulling filtered frame from filters\n");
	424	ret = av_buffersink_get_frame(filter_ctx[stream_index].buffersink_ctx,
	425	filt_frame);
	426	if (ret < 0) {
	427	/* if no more frames for output - returns AVERROR(EAGAIN)
	428	* if flushed and no more frames for output - returns AVERROR_EOF
	429	* rewrite retcode to 0 to show it as normal procedure completion
	430	*/
	431	if (ret == AVERROR(EAGAIN) \|\| ret == AVERROR_EOF)
	432	ret = 0;
	433	av_frame_free(&filt_frame);
	434	break;
	435	}
	436
	437	filt_frame->pict_type = AV_PICTURE_TYPE_NONE;
	438	ret = encode_write_frame(filt_frame, stream_index, NULL);
	439	if (ret < 0)
	440	break;
	441	}
	442
	443	return ret;
	444	}
	445
	446	static int flush_encoder(unsigned int stream_index)
	447	{
	448	int ret;
	449	int got_frame;
	450
	451	if (!(ofmt_ctx->streams[stream_index]->codec->codec->capabilities &
	452	CODEC_CAP_DELAY))
	453	return 0;
	454
	455	while (1) {
	456	av_log(NULL, AV_LOG_INFO, "Flushing stream #%u encoder\n", stream_index);
	457	ret = encode_write_frame(NULL, stream_index, &got_frame);
	458	if (ret < 0)
459	break;
460	if (!got_frame)
461	return 0;
462	}
463	return ret;
464	}
465
466	int main(int argc, char **argv)
467	{
468	int ret;
469	AVPacket packet = { .data = NULL, .size = 0 };
470	AVFrame *frame = NULL;
471	enum AVMediaType type;
472	unsigned int stream_index;
473	unsigned int i;
474	int got_frame;
475	int (dec_func)(AVCodecContext , AVFrame , int , const AVPacket *);
476
477	if (argc != 3) {
478	av_log(NULL, AV_LOG_ERROR, "Usage: %s <input file> <output file>\n", argv[0]);
479	return 1;
480	}
481
482	av_register_all();
483	avfilter_register_all();
484
485	if ((ret = open_input_file(argv[1])) < 0)
486	goto end;
487	if ((ret = open_output_file(argv[2])) < 0)
488	goto end;
489	if ((ret = init_filters()) < 0)
490	goto end;
491
492	/* read all packets */
493	while (1) {
494	if ((ret = av_read_frame(ifmt_ctx, &packet)) < 0)
495	break;
496	stream_index = packet.stream_index;
497	type = ifmt_ctx->streams[packet.stream_index]->codec->codec_type;
498	av_log(NULL, AV_LOG_DEBUG, "Demuxer gave frame of stream_index %u\n",
499	stream_index);
500
501	if (filter_ctx[stream_index].filter_graph) {
502	av_log(NULL, AV_LOG_DEBUG, "Going to reencode&filter the frame\n");
503	frame = av_frame_alloc();
504	if (!frame) {
505	ret = AVERROR(ENOMEM);
506	break;
507	}
f6fa7814 DM	508	av_packet_rescale_ts(&packet,
	509	ifmt_ctx->streams[stream_index]->time_base,
	510	ifmt_ctx->streams[stream_index]->codec->time_base);
2ba45a60 DM	511	dec_func = (type == AVMEDIA_TYPE_VIDEO) ? avcodec_decode_video2 :
	512	avcodec_decode_audio4;
	513	ret = dec_func(ifmt_ctx->streams[stream_index]->codec, frame,
	514	&got_frame, &packet);
	515	if (ret < 0) {
	516	av_frame_free(&frame);
	517	av_log(NULL, AV_LOG_ERROR, "Decoding failed\n");
	518	break;
	519	}
	520
	521	if (got_frame) {
	522	frame->pts = av_frame_get_best_effort_timestamp(frame);
	523	ret = filter_encode_write_frame(frame, stream_index);
	524	av_frame_free(&frame);
	525	if (ret < 0)
	526	goto end;
	527	} else {
	528	av_frame_free(&frame);
	529	}
	530	} else {
	531	/* remux this frame without reencoding */
f6fa7814 DM	532	av_packet_rescale_ts(&packet,
	533	ifmt_ctx->streams[stream_index]->time_base,
	534	ofmt_ctx->streams[stream_index]->time_base);
2ba45a60 DM	535
	536	ret = av_interleaved_write_frame(ofmt_ctx, &packet);
	537	if (ret < 0)
	538	goto end;
	539	}
	540	av_free_packet(&packet);
	541	}
	542
	543	/* flush filters and encoders */
	544	for (i = 0; i < ifmt_ctx->nb_streams; i++) {
	545	/* flush filter */
	546	if (!filter_ctx[i].filter_graph)
	547	continue;
	548	ret = filter_encode_write_frame(NULL, i);
	549	if (ret < 0) {
	550	av_log(NULL, AV_LOG_ERROR, "Flushing filter failed\n");
	551	goto end;
	552	}
	553
	554	/* flush encoder */
	555	ret = flush_encoder(i);
	556	if (ret < 0) {
	557	av_log(NULL, AV_LOG_ERROR, "Flushing encoder failed\n");
	558	goto end;
	559	}
	560	}
	561
	562	av_write_trailer(ofmt_ctx);
	563	end:
	564	av_free_packet(&packet);
	565	av_frame_free(&frame);
	566	for (i = 0; i < ifmt_ctx->nb_streams; i++) {
	567	avcodec_close(ifmt_ctx->streams[i]->codec);
	568	if (ofmt_ctx && ofmt_ctx->nb_streams > i && ofmt_ctx->streams[i] && ofmt_ctx->streams[i]->codec)
	569	avcodec_close(ofmt_ctx->streams[i]->codec);
	570	if (filter_ctx && filter_ctx[i].filter_graph)
	571	avfilter_graph_free(&filter_ctx[i].filter_graph);
	572	}
	573	av_free(filter_ctx);
	574	avformat_close_input(&ifmt_ctx);
	575	if (ofmt_ctx && !(ofmt_ctx->oformat->flags & AVFMT_NOFILE))
	576	avio_close(ofmt_ctx->pb);
	577	avformat_free_context(ofmt_ctx);
	578
	579	if (ret < 0)
	580	av_log(NULL, AV_LOG_ERROR, "Error occurred: %s\n", av_err2str(ret));
	581
	582	return ret ? 1 : 0;
	583	}