| 1 | /* |
| 2 | * Copyright (c) 2007 Bobby Bingham |
| 3 | * |
| 4 | * This file is part of FFmpeg. |
| 5 | * |
| 6 | * FFmpeg is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU Lesser General Public |
| 8 | * License as published by the Free Software Foundation; either |
| 9 | * version 2.1 of the License, or (at your option) any later version. |
| 10 | * |
| 11 | * FFmpeg is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | * Lesser General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Lesser General Public |
| 17 | * License along with FFmpeg; if not, write to the Free Software |
| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 19 | */ |
| 20 | |
| 21 | /** |
| 22 | * @file |
| 23 | * FIFO buffering filter |
| 24 | */ |
| 25 | |
| 26 | #include "libavutil/avassert.h" |
| 27 | #include "libavutil/channel_layout.h" |
| 28 | #include "libavutil/common.h" |
| 29 | #include "libavutil/mathematics.h" |
| 30 | #include "libavutil/samplefmt.h" |
| 31 | |
| 32 | #include "audio.h" |
| 33 | #include "avfilter.h" |
| 34 | #include "internal.h" |
| 35 | #include "video.h" |
| 36 | |
| 37 | typedef struct Buf { |
| 38 | AVFrame *frame; |
| 39 | struct Buf *next; |
| 40 | } Buf; |
| 41 | |
| 42 | typedef struct FifoContext { |
| 43 | Buf root; |
| 44 | Buf *last; ///< last buffered frame |
| 45 | |
| 46 | /** |
| 47 | * When a specific number of output samples is requested, the partial |
| 48 | * buffer is stored here |
| 49 | */ |
| 50 | AVFrame *out; |
| 51 | int allocated_samples; ///< number of samples out was allocated for |
| 52 | } FifoContext; |
| 53 | |
| 54 | static av_cold int init(AVFilterContext *ctx) |
| 55 | { |
| 56 | FifoContext *fifo = ctx->priv; |
| 57 | fifo->last = &fifo->root; |
| 58 | |
| 59 | return 0; |
| 60 | } |
| 61 | |
| 62 | static av_cold void uninit(AVFilterContext *ctx) |
| 63 | { |
| 64 | FifoContext *fifo = ctx->priv; |
| 65 | Buf *buf, *tmp; |
| 66 | |
| 67 | for (buf = fifo->root.next; buf; buf = tmp) { |
| 68 | tmp = buf->next; |
| 69 | av_frame_free(&buf->frame); |
| 70 | av_free(buf); |
| 71 | } |
| 72 | |
| 73 | av_frame_free(&fifo->out); |
| 74 | } |
| 75 | |
| 76 | static int add_to_queue(AVFilterLink *inlink, AVFrame *frame) |
| 77 | { |
| 78 | FifoContext *fifo = inlink->dst->priv; |
| 79 | |
| 80 | fifo->last->next = av_mallocz(sizeof(Buf)); |
| 81 | if (!fifo->last->next) { |
| 82 | av_frame_free(&frame); |
| 83 | return AVERROR(ENOMEM); |
| 84 | } |
| 85 | |
| 86 | fifo->last = fifo->last->next; |
| 87 | fifo->last->frame = frame; |
| 88 | |
| 89 | return 0; |
| 90 | } |
| 91 | |
| 92 | static void queue_pop(FifoContext *s) |
| 93 | { |
| 94 | Buf *tmp = s->root.next->next; |
| 95 | if (s->last == s->root.next) |
| 96 | s->last = &s->root; |
| 97 | av_freep(&s->root.next); |
| 98 | s->root.next = tmp; |
| 99 | } |
| 100 | |
| 101 | /** |
| 102 | * Move data pointers and pts offset samples forward. |
| 103 | */ |
| 104 | static void buffer_offset(AVFilterLink *link, AVFrame *frame, |
| 105 | int offset) |
| 106 | { |
| 107 | int nb_channels = av_get_channel_layout_nb_channels(link->channel_layout); |
| 108 | int planar = av_sample_fmt_is_planar(link->format); |
| 109 | int planes = planar ? nb_channels : 1; |
| 110 | int block_align = av_get_bytes_per_sample(link->format) * (planar ? 1 : nb_channels); |
| 111 | int i; |
| 112 | |
| 113 | av_assert0(frame->nb_samples > offset); |
| 114 | |
| 115 | for (i = 0; i < planes; i++) |
| 116 | frame->extended_data[i] += block_align * offset; |
| 117 | if (frame->data != frame->extended_data) |
| 118 | memcpy(frame->data, frame->extended_data, |
| 119 | FFMIN(planes, FF_ARRAY_ELEMS(frame->data)) * sizeof(*frame->data)); |
| 120 | frame->linesize[0] -= block_align*offset; |
| 121 | frame->nb_samples -= offset; |
| 122 | |
| 123 | if (frame->pts != AV_NOPTS_VALUE) { |
| 124 | frame->pts += av_rescale_q(offset, (AVRational){1, link->sample_rate}, |
| 125 | link->time_base); |
| 126 | } |
| 127 | } |
| 128 | |
| 129 | static int calc_ptr_alignment(AVFrame *frame) |
| 130 | { |
| 131 | int planes = av_sample_fmt_is_planar(frame->format) ? |
| 132 | av_get_channel_layout_nb_channels(frame->channel_layout) : 1; |
| 133 | int min_align = 128; |
| 134 | int p; |
| 135 | |
| 136 | for (p = 0; p < planes; p++) { |
| 137 | int cur_align = 128; |
| 138 | while ((intptr_t)frame->extended_data[p] % cur_align) |
| 139 | cur_align >>= 1; |
| 140 | if (cur_align < min_align) |
| 141 | min_align = cur_align; |
| 142 | } |
| 143 | return min_align; |
| 144 | } |
| 145 | |
| 146 | static int return_audio_frame(AVFilterContext *ctx) |
| 147 | { |
| 148 | AVFilterLink *link = ctx->outputs[0]; |
| 149 | FifoContext *s = ctx->priv; |
| 150 | AVFrame *head = s->root.next ? s->root.next->frame : NULL; |
| 151 | AVFrame *out; |
| 152 | int ret; |
| 153 | |
| 154 | /* if head is NULL then we're flushing the remaining samples in out */ |
| 155 | if (!head && !s->out) |
| 156 | return AVERROR_EOF; |
| 157 | |
| 158 | if (!s->out && |
| 159 | head->nb_samples >= link->request_samples && |
| 160 | calc_ptr_alignment(head) >= 32) { |
| 161 | if (head->nb_samples == link->request_samples) { |
| 162 | out = head; |
| 163 | queue_pop(s); |
| 164 | } else { |
| 165 | out = av_frame_clone(head); |
| 166 | if (!out) |
| 167 | return AVERROR(ENOMEM); |
| 168 | |
| 169 | out->nb_samples = link->request_samples; |
| 170 | buffer_offset(link, head, link->request_samples); |
| 171 | } |
| 172 | } else { |
| 173 | int nb_channels = av_get_channel_layout_nb_channels(link->channel_layout); |
| 174 | |
| 175 | if (!s->out) { |
| 176 | s->out = ff_get_audio_buffer(link, link->request_samples); |
| 177 | if (!s->out) |
| 178 | return AVERROR(ENOMEM); |
| 179 | |
| 180 | s->out->nb_samples = 0; |
| 181 | s->out->pts = head->pts; |
| 182 | s->allocated_samples = link->request_samples; |
| 183 | } else if (link->request_samples != s->allocated_samples) { |
| 184 | av_log(ctx, AV_LOG_ERROR, "request_samples changed before the " |
| 185 | "buffer was returned.\n"); |
| 186 | return AVERROR(EINVAL); |
| 187 | } |
| 188 | |
| 189 | while (s->out->nb_samples < s->allocated_samples) { |
| 190 | int len; |
| 191 | |
| 192 | if (!s->root.next) { |
| 193 | ret = ff_request_frame(ctx->inputs[0]); |
| 194 | if (ret == AVERROR_EOF) { |
| 195 | av_samples_set_silence(s->out->extended_data, |
| 196 | s->out->nb_samples, |
| 197 | s->allocated_samples - |
| 198 | s->out->nb_samples, |
| 199 | nb_channels, link->format); |
| 200 | s->out->nb_samples = s->allocated_samples; |
| 201 | break; |
| 202 | } else if (ret < 0) |
| 203 | return ret; |
| 204 | av_assert0(s->root.next); // If ff_request_frame() succeeded then we should have a frame |
| 205 | } |
| 206 | head = s->root.next->frame; |
| 207 | |
| 208 | len = FFMIN(s->allocated_samples - s->out->nb_samples, |
| 209 | head->nb_samples); |
| 210 | |
| 211 | av_samples_copy(s->out->extended_data, head->extended_data, |
| 212 | s->out->nb_samples, 0, len, nb_channels, |
| 213 | link->format); |
| 214 | s->out->nb_samples += len; |
| 215 | |
| 216 | if (len == head->nb_samples) { |
| 217 | av_frame_free(&head); |
| 218 | queue_pop(s); |
| 219 | } else { |
| 220 | buffer_offset(link, head, len); |
| 221 | } |
| 222 | } |
| 223 | out = s->out; |
| 224 | s->out = NULL; |
| 225 | } |
| 226 | return ff_filter_frame(link, out); |
| 227 | } |
| 228 | |
| 229 | static int request_frame(AVFilterLink *outlink) |
| 230 | { |
| 231 | FifoContext *fifo = outlink->src->priv; |
| 232 | int ret = 0; |
| 233 | |
| 234 | if (!fifo->root.next) { |
| 235 | if ((ret = ff_request_frame(outlink->src->inputs[0])) < 0) { |
| 236 | if (ret == AVERROR_EOF && outlink->request_samples) |
| 237 | return return_audio_frame(outlink->src); |
| 238 | return ret; |
| 239 | } |
| 240 | av_assert0(fifo->root.next); |
| 241 | } |
| 242 | |
| 243 | if (outlink->request_samples) { |
| 244 | return return_audio_frame(outlink->src); |
| 245 | } else { |
| 246 | ret = ff_filter_frame(outlink, fifo->root.next->frame); |
| 247 | queue_pop(fifo); |
| 248 | } |
| 249 | |
| 250 | return ret; |
| 251 | } |
| 252 | |
| 253 | static const AVFilterPad avfilter_vf_fifo_inputs[] = { |
| 254 | { |
| 255 | .name = "default", |
| 256 | .type = AVMEDIA_TYPE_VIDEO, |
| 257 | .filter_frame = add_to_queue, |
| 258 | }, |
| 259 | { NULL } |
| 260 | }; |
| 261 | |
| 262 | static const AVFilterPad avfilter_vf_fifo_outputs[] = { |
| 263 | { |
| 264 | .name = "default", |
| 265 | .type = AVMEDIA_TYPE_VIDEO, |
| 266 | .request_frame = request_frame, |
| 267 | }, |
| 268 | { NULL } |
| 269 | }; |
| 270 | |
| 271 | AVFilter ff_vf_fifo = { |
| 272 | .name = "fifo", |
| 273 | .description = NULL_IF_CONFIG_SMALL("Buffer input images and send them when they are requested."), |
| 274 | |
| 275 | .init = init, |
| 276 | .uninit = uninit, |
| 277 | |
| 278 | .priv_size = sizeof(FifoContext), |
| 279 | |
| 280 | .inputs = avfilter_vf_fifo_inputs, |
| 281 | .outputs = avfilter_vf_fifo_outputs, |
| 282 | }; |
| 283 | |
| 284 | static const AVFilterPad avfilter_af_afifo_inputs[] = { |
| 285 | { |
| 286 | .name = "default", |
| 287 | .type = AVMEDIA_TYPE_AUDIO, |
| 288 | .filter_frame = add_to_queue, |
| 289 | }, |
| 290 | { NULL } |
| 291 | }; |
| 292 | |
| 293 | static const AVFilterPad avfilter_af_afifo_outputs[] = { |
| 294 | { |
| 295 | .name = "default", |
| 296 | .type = AVMEDIA_TYPE_AUDIO, |
| 297 | .request_frame = request_frame, |
| 298 | }, |
| 299 | { NULL } |
| 300 | }; |
| 301 | |
| 302 | AVFilter ff_af_afifo = { |
| 303 | .name = "afifo", |
| 304 | .description = NULL_IF_CONFIG_SMALL("Buffer input frames and send them when they are requested."), |
| 305 | |
| 306 | .init = init, |
| 307 | .uninit = uninit, |
| 308 | |
| 309 | .priv_size = sizeof(FifoContext), |
| 310 | |
| 311 | .inputs = avfilter_af_afifo_inputs, |
| 312 | .outputs = avfilter_af_afifo_outputs, |
| 313 | }; |