FFmpeg: libavdevice/lavfi.c Source File

00001 /*
00002  * Copyright (c) 2011 Stefano Sabatini
00003  *
00004  * This file is part of FFmpeg.
00005  *
00006  * FFmpeg is free software; you can redistribute it and/or
00007  * modify it under the terms of the GNU Lesser General Public
00008  * License as published by the Free Software Foundation; either
00009  * version 2.1 of the License, or (at your option) any later version.
00010  *
00011  * FFmpeg is distributed in the hope that it will be useful,
00012  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014  * Lesser General Public License for more details.
00015  *
00016  * You should have received a copy of the GNU Lesser General Public
00017  * License along with FFmpeg; if not, write to the Free Software
00018  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00019  */
00020 
00026 /* #define DEBUG */
00027 
00028 #include <float.h>              /* DBL_MIN, DBL_MAX */
00029 
00030 #include "libavutil/bprint.h"
00031 #include "libavutil/channel_layout.h"
00032 #include "libavutil/file.h"
00033 #include "libavutil/log.h"
00034 #include "libavutil/mem.h"
00035 #include "libavutil/opt.h"
00036 #include "libavutil/parseutils.h"
00037 #include "libavutil/pixdesc.h"
00038 #include "libavfilter/avfilter.h"
00039 #include "libavfilter/avfiltergraph.h"
00040 #include "libavfilter/buffersink.h"
00041 #include "libavformat/internal.h"
00042 #include "avdevice.h"
00043 
00044 typedef struct {
00045     AVClass *class;          
00046     char          *graph_str;
00047     char          *graph_filename;
00048     char          *dump_graph;
00049     AVFilterGraph *graph;
00050     AVFilterContext **sinks;
00051     int *sink_stream_map;
00052     int *sink_eof;
00053     int *stream_sink_map;
00054 } LavfiContext;
00055 
00056 static int *create_all_formats(int n)
00057 {
00058     int i, j, *fmts, count = 0;
00059 
00060     for (i = 0; i < n; i++) {
00061         const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(i);
00062         if (!(desc->flags & PIX_FMT_HWACCEL))
00063             count++;
00064     }
00065 
00066     if (!(fmts = av_malloc((count+1) * sizeof(int))))
00067         return NULL;
00068     for (j = 0, i = 0; i < n; i++) {
00069         const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(i);
00070         if (!(desc->flags & PIX_FMT_HWACCEL))
00071             fmts[j++] = i;
00072     }
00073     fmts[j] = -1;
00074     return fmts;
00075 }
00076 
00077 av_cold static int lavfi_read_close(AVFormatContext *avctx)
00078 {
00079     LavfiContext *lavfi = avctx->priv_data;
00080 
00081     av_freep(&lavfi->sink_stream_map);
00082     av_freep(&lavfi->sink_eof);
00083     av_freep(&lavfi->stream_sink_map);
00084     av_freep(&lavfi->sinks);
00085     avfilter_graph_free(&lavfi->graph);
00086 
00087     return 0;
00088 }
00089 
00090 av_cold static int lavfi_read_header(AVFormatContext *avctx)
00091 {
00092     LavfiContext *lavfi = avctx->priv_data;
00093     AVFilterInOut *input_links = NULL, *output_links = NULL, *inout;
00094     AVFilter *buffersink, *abuffersink;
00095     int *pix_fmts = create_all_formats(AV_PIX_FMT_NB);
00096     enum AVMediaType type;
00097     int ret = 0, i, n;
00098 
00099 #define FAIL(ERR) { ret = ERR; goto end; }
00100 
00101     if (!pix_fmts)
00102         FAIL(AVERROR(ENOMEM));
00103 
00104     avfilter_register_all();
00105 
00106     buffersink = avfilter_get_by_name("ffbuffersink");
00107     abuffersink = avfilter_get_by_name("ffabuffersink");
00108 
00109     if (lavfi->graph_filename && lavfi->graph_str) {
00110         av_log(avctx, AV_LOG_ERROR,
00111                "Only one of the graph or graph_file options must be specified\n");
00112         FAIL(AVERROR(EINVAL));
00113     }
00114 
00115     if (lavfi->graph_filename) {
00116         uint8_t *file_buf, *graph_buf;
00117         size_t file_bufsize;
00118         ret = av_file_map(lavfi->graph_filename,
00119                           &file_buf, &file_bufsize, 0, avctx);
00120         if (ret < 0)
00121             goto end;
00122 
00123         /* create a 0-terminated string based on the read file */
00124         graph_buf = av_malloc(file_bufsize + 1);
00125         if (!graph_buf) {
00126             av_file_unmap(file_buf, file_bufsize);
00127             FAIL(AVERROR(ENOMEM));
00128         }
00129         memcpy(graph_buf, file_buf, file_bufsize);
00130         graph_buf[file_bufsize] = 0;
00131         av_file_unmap(file_buf, file_bufsize);
00132         lavfi->graph_str = graph_buf;
00133     }
00134 
00135     if (!lavfi->graph_str)
00136         lavfi->graph_str = av_strdup(avctx->filename);
00137 
00138     /* parse the graph, create a stream for each open output */
00139     if (!(lavfi->graph = avfilter_graph_alloc()))
00140         FAIL(AVERROR(ENOMEM));
00141 
00142     if ((ret = avfilter_graph_parse(lavfi->graph, lavfi->graph_str,
00143                                     &input_links, &output_links, avctx)) < 0)
00144         FAIL(ret);
00145 
00146     if (input_links) {
00147         av_log(avctx, AV_LOG_ERROR,
00148                "Open inputs in the filtergraph are not acceptable\n");
00149         FAIL(AVERROR(EINVAL));
00150     }
00151 
00152     /* count the outputs */
00153     for (n = 0, inout = output_links; inout; n++, inout = inout->next);
00154 
00155     if (!(lavfi->sink_stream_map = av_malloc(sizeof(int) * n)))
00156         FAIL(AVERROR(ENOMEM));
00157     if (!(lavfi->sink_eof = av_mallocz(sizeof(int) * n)))
00158         FAIL(AVERROR(ENOMEM));
00159     if (!(lavfi->stream_sink_map = av_malloc(sizeof(int) * n)))
00160         FAIL(AVERROR(ENOMEM));
00161 
00162     for (i = 0; i < n; i++)
00163         lavfi->stream_sink_map[i] = -1;
00164 
00165     /* parse the output link names - they need to be of the form out0, out1, ...
00166      * create a mapping between them and the streams */
00167     for (i = 0, inout = output_links; inout; i++, inout = inout->next) {
00168         int stream_idx;
00169         if (!strcmp(inout->name, "out"))
00170             stream_idx = 0;
00171         else if (sscanf(inout->name, "out%d\n", &stream_idx) != 1) {
00172             av_log(avctx,  AV_LOG_ERROR,
00173                    "Invalid outpad name '%s'\n", inout->name);
00174             FAIL(AVERROR(EINVAL));
00175         }
00176 
00177         if ((unsigned)stream_idx >= n) {
00178             av_log(avctx, AV_LOG_ERROR,
00179                    "Invalid index was specified in output '%s', "
00180                    "must be a non-negative value < %d\n",
00181                    inout->name, n);
00182             FAIL(AVERROR(EINVAL));
00183         }
00184 
00185         /* is an audio or video output? */
00186         type = inout->filter_ctx->output_pads[inout->pad_idx].type;
00187         if (type != AVMEDIA_TYPE_VIDEO && type != AVMEDIA_TYPE_AUDIO) {
00188             av_log(avctx,  AV_LOG_ERROR,
00189                    "Output '%s' is not a video or audio output, not yet supported\n", inout->name);
00190             FAIL(AVERROR(EINVAL));
00191         }
00192 
00193         if (lavfi->stream_sink_map[stream_idx] != -1) {
00194             av_log(avctx,  AV_LOG_ERROR,
00195                    "An output with stream index %d was already specified\n",
00196                    stream_idx);
00197             FAIL(AVERROR(EINVAL));
00198         }
00199         lavfi->sink_stream_map[i] = stream_idx;
00200         lavfi->stream_sink_map[stream_idx] = i;
00201     }
00202 
00203     /* for each open output create a corresponding stream */
00204     for (i = 0, inout = output_links; inout; i++, inout = inout->next) {
00205         AVStream *st;
00206         if (!(st = avformat_new_stream(avctx, NULL)))
00207             FAIL(AVERROR(ENOMEM));
00208         st->id = i;
00209     }
00210 
00211     /* create a sink for each output and connect them to the graph */
00212     lavfi->sinks = av_malloc(sizeof(AVFilterContext *) * avctx->nb_streams);
00213     if (!lavfi->sinks)
00214         FAIL(AVERROR(ENOMEM));
00215 
00216     for (i = 0, inout = output_links; inout; i++, inout = inout->next) {
00217         AVFilterContext *sink;
00218 
00219         type = inout->filter_ctx->output_pads[inout->pad_idx].type;
00220 
00221         if (type == AVMEDIA_TYPE_VIDEO && ! buffersink ||
00222             type == AVMEDIA_TYPE_AUDIO && ! abuffersink) {
00223                 av_log(avctx, AV_LOG_ERROR, "Missing required buffersink filter, aborting.\n");
00224                 FAIL(AVERROR_FILTER_NOT_FOUND);
00225         }
00226 
00227         if (type == AVMEDIA_TYPE_VIDEO) {
00228             AVBufferSinkParams *buffersink_params = av_buffersink_params_alloc();
00229 
00230             buffersink_params->pixel_fmts = pix_fmts;
00231             ret = avfilter_graph_create_filter(&sink, buffersink,
00232                                                inout->name, NULL,
00233                                                buffersink_params, lavfi->graph);
00234             av_freep(&buffersink_params);
00235 
00236             if (ret < 0)
00237                 goto end;
00238         } else if (type == AVMEDIA_TYPE_AUDIO) {
00239             enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_U8,
00240                                                   AV_SAMPLE_FMT_S16,
00241                                                   AV_SAMPLE_FMT_S32,
00242                                                   AV_SAMPLE_FMT_FLT,
00243                                                   AV_SAMPLE_FMT_DBL, -1 };
00244             AVABufferSinkParams *abuffersink_params = av_abuffersink_params_alloc();
00245             abuffersink_params->sample_fmts = sample_fmts;
00246 
00247             ret = avfilter_graph_create_filter(&sink, abuffersink,
00248                                                inout->name, NULL,
00249                                                abuffersink_params, lavfi->graph);
00250             av_free(abuffersink_params);
00251             if (ret < 0)
00252                 goto end;
00253         }
00254 
00255         lavfi->sinks[i] = sink;
00256         if ((ret = avfilter_link(inout->filter_ctx, inout->pad_idx, sink, 0)) < 0)
00257             FAIL(ret);
00258     }
00259 
00260     /* configure the graph */
00261     if ((ret = avfilter_graph_config(lavfi->graph, avctx)) < 0)
00262         FAIL(ret);
00263 
00264     if (lavfi->dump_graph) {
00265         char *dump = avfilter_graph_dump(lavfi->graph, lavfi->dump_graph);
00266         fputs(dump, stderr);
00267         fflush(stderr);
00268         av_free(dump);
00269     }
00270 
00271     /* fill each stream with the information in the corresponding sink */
00272     for (i = 0; i < avctx->nb_streams; i++) {
00273         AVFilterLink *link = lavfi->sinks[lavfi->stream_sink_map[i]]->inputs[0];
00274         AVStream *st = avctx->streams[i];
00275         st->codec->codec_type = link->type;
00276         avpriv_set_pts_info(st, 64, link->time_base.num, link->time_base.den);
00277         if (link->type == AVMEDIA_TYPE_VIDEO) {
00278             st->codec->codec_id   = AV_CODEC_ID_RAWVIDEO;
00279             st->codec->pix_fmt    = link->format;
00280             st->codec->time_base  = link->time_base;
00281             st->codec->width      = link->w;
00282             st->codec->height     = link->h;
00283             st       ->sample_aspect_ratio =
00284             st->codec->sample_aspect_ratio = link->sample_aspect_ratio;
00285         } else if (link->type == AVMEDIA_TYPE_AUDIO) {
00286             st->codec->codec_id    = av_get_pcm_codec(link->format, -1);
00287             st->codec->channels    = av_get_channel_layout_nb_channels(link->channel_layout);
00288             st->codec->sample_fmt  = link->format;
00289             st->codec->sample_rate = link->sample_rate;
00290             st->codec->time_base   = link->time_base;
00291             st->codec->channel_layout = link->channel_layout;
00292             if (st->codec->codec_id == AV_CODEC_ID_NONE)
00293                 av_log(avctx, AV_LOG_ERROR,
00294                        "Could not find PCM codec for sample format %s.\n",
00295                        av_get_sample_fmt_name(link->format));
00296         }
00297     }
00298 
00299 end:
00300     av_free(pix_fmts);
00301     avfilter_inout_free(&input_links);
00302     avfilter_inout_free(&output_links);
00303     if (ret < 0)
00304         lavfi_read_close(avctx);
00305     return ret;
00306 }
00307 
00308 static int lavfi_read_packet(AVFormatContext *avctx, AVPacket *pkt)
00309 {
00310     LavfiContext *lavfi = avctx->priv_data;
00311     double min_pts = DBL_MAX;
00312     int stream_idx, min_pts_sink_idx = 0;
00313     AVFilterBufferRef *ref;
00314     AVPicture pict;
00315     int ret, i;
00316     int size = 0;
00317 
00318     /* iterate through all the graph sinks. Select the sink with the
00319      * minimum PTS */
00320     for (i = 0; i < avctx->nb_streams; i++) {
00321         AVRational tb = lavfi->sinks[i]->inputs[0]->time_base;
00322         double d;
00323         int ret;
00324 
00325         if (lavfi->sink_eof[i])
00326             continue;
00327 
00328         ret = av_buffersink_get_buffer_ref(lavfi->sinks[i],
00329                                        &ref, AV_BUFFERSINK_FLAG_PEEK);
00330         if (ret == AVERROR_EOF) {
00331             av_dlog(avctx, "EOF sink_idx:%d\n", i);
00332             lavfi->sink_eof[i] = 1;
00333             continue;
00334         } else if (ret < 0)
00335             return ret;
00336         d = av_rescale_q(ref->pts, tb, AV_TIME_BASE_Q);
00337         av_dlog(avctx, "sink_idx:%d time:%f\n", i, d);
00338 
00339         if (d < min_pts) {
00340             min_pts = d;
00341             min_pts_sink_idx = i;
00342         }
00343     }
00344     if (min_pts == DBL_MAX)
00345         return AVERROR_EOF;
00346 
00347     av_dlog(avctx, "min_pts_sink_idx:%i\n", min_pts_sink_idx);
00348 
00349     av_buffersink_get_buffer_ref(lavfi->sinks[min_pts_sink_idx], &ref, 0);
00350     stream_idx = lavfi->sink_stream_map[min_pts_sink_idx];
00351 
00352     if (ref->video) {
00353         size = avpicture_get_size(ref->format, ref->video->w, ref->video->h);
00354         if ((ret = av_new_packet(pkt, size)) < 0)
00355             return ret;
00356 
00357         memcpy(pict.data,     ref->data,     4*sizeof(ref->data[0]));
00358         memcpy(pict.linesize, ref->linesize, 4*sizeof(ref->linesize[0]));
00359 
00360         avpicture_layout(&pict, ref->format, ref->video->w,
00361                          ref->video->h, pkt->data, size);
00362     } else if (ref->audio) {
00363         size = ref->audio->nb_samples *
00364             av_get_bytes_per_sample(ref->format) *
00365             av_get_channel_layout_nb_channels(ref->audio->channel_layout);
00366         if ((ret = av_new_packet(pkt, size)) < 0)
00367             return ret;
00368         memcpy(pkt->data, ref->data[0], size);
00369     }
00370 
00371     if (ref->metadata) {
00372         uint8_t *metadata;
00373         AVDictionaryEntry *e = NULL;
00374         AVBPrint meta_buf;
00375 
00376         av_bprint_init(&meta_buf, 0, AV_BPRINT_SIZE_UNLIMITED);
00377         while ((e = av_dict_get(ref->metadata, "", e, AV_DICT_IGNORE_SUFFIX))) {
00378             av_bprintf(&meta_buf, "%s", e->key);
00379             av_bprint_chars(&meta_buf, '\0', 1);
00380             av_bprintf(&meta_buf, "%s", e->value);
00381             av_bprint_chars(&meta_buf, '\0', 1);
00382         }
00383         if (!av_bprint_is_complete(&meta_buf) ||
00384             !(metadata = av_packet_new_side_data(pkt, AV_PKT_DATA_STRINGS_METADATA,
00385                                                  meta_buf.len))) {
00386             av_bprint_finalize(&meta_buf, NULL);
00387             return AVERROR(ENOMEM);
00388         }
00389         memcpy(metadata, meta_buf.str, meta_buf.len);
00390         av_bprint_finalize(&meta_buf, NULL);
00391     }
00392 
00393     pkt->stream_index = stream_idx;
00394     pkt->pts = ref->pts;
00395     pkt->pos = ref->pos;
00396     pkt->size = size;
00397     avfilter_unref_buffer(ref);
00398     return size;
00399 }
00400 
00401 #define OFFSET(x) offsetof(LavfiContext, x)
00402 
00403 #define DEC AV_OPT_FLAG_DECODING_PARAM
00404 
00405 static const AVOption options[] = {
00406     { "graph",     "set libavfilter graph", OFFSET(graph_str),  AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
00407     { "graph_file","set libavfilter graph filename", OFFSET(graph_filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC},
00408     { "dumpgraph", "dump graph to stderr",  OFFSET(dump_graph), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
00409     { NULL },
00410 };
00411 
00412 static const AVClass lavfi_class = {
00413     .class_name = "lavfi indev",
00414     .item_name  = av_default_item_name,
00415     .option     = options,
00416     .version    = LIBAVUTIL_VERSION_INT,
00417 };
00418 
00419 AVInputFormat ff_lavfi_demuxer = {
00420     .name           = "lavfi",
00421     .long_name      = NULL_IF_CONFIG_SMALL("Libavfilter virtual input device"),
00422     .priv_data_size = sizeof(LavfiContext),
00423     .read_header    = lavfi_read_header,
00424     .read_packet    = lavfi_read_packet,
00425     .read_close     = lavfi_read_close,
00426     .flags          = AVFMT_NOFILE,
00427     .priv_class     = &lavfi_class,
00428 };