guint gst_v4l2_allocator_start (GstV4l2Allocator * allocator, guint32 count, guint32 memory) { struct v4l2_requestbuffers breq = { count, allocator->type, memory }; gboolean can_allocate; gint i; g_return_val_if_fail (count != 0, 0); GST_OBJECT_LOCK (allocator); if (g_atomic_int_get (&allocator->active)) goto already_active; if (v4l2_ioctl (allocator->video_fd, VIDIOC_REQBUFS, &breq) < 0) goto reqbufs_failed; if (breq.count < 1) goto out_of_memory; switch (memory) { case V4L2_MEMORY_MMAP: can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (allocator, MMAP); break; case V4L2_MEMORY_USERPTR: can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (allocator, USERPTR); break; case V4L2_MEMORY_DMABUF: can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (allocator, DMABUF); break; default: can_allocate = FALSE; break; } GST_DEBUG_OBJECT (allocator, "allocated %u %s buffers out of %u requested", breq.count, memory_type_to_str (memory), count); allocator->can_allocate = can_allocate; allocator->count = breq.count; allocator->memory = memory; /* Create memory groups */ for (i = 0; i < allocator->count; i++) { allocator->groups[i] = gst_v4l2_memory_group_new (allocator, i); if (allocator->groups[i] == NULL) goto error; gst_atomic_queue_push (allocator->free_queue, allocator->groups[i]); } g_atomic_int_set (&allocator->active, TRUE); done: GST_OBJECT_UNLOCK (allocator); return breq.count; already_active: { GST_ERROR_OBJECT (allocator, "allocator already active"); goto error; } reqbufs_failed: { GST_ERROR_OBJECT (allocator, "error requesting %d buffers: %s", count, g_strerror (errno)); goto error; } out_of_memory: { GST_ERROR_OBJECT (allocator, "Not enough memory to allocate buffers"); goto error; } error: { breq.count = 0; goto done; } }
static gboolean gst_v4l2_buffer_pool_set_config (GstBufferPool * bpool, GstStructure * config) { GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool); GstV4l2Object *obj = pool->obj; GstCaps *caps; guint size, min_buffers, max_buffers; GstAllocator *allocator; GstAllocationParams params; gboolean can_allocate = FALSE; gboolean updated = FALSE; gboolean ret; pool->add_videometa = gst_buffer_pool_config_has_option (config, GST_BUFFER_POOL_OPTION_VIDEO_META); /* parse the config and keep around */ if (!gst_buffer_pool_config_get_params (config, &caps, &size, &min_buffers, &max_buffers)) goto wrong_config; if (!gst_buffer_pool_config_get_allocator (config, &allocator, ¶ms)) goto wrong_config; GST_DEBUG_OBJECT (pool, "config %" GST_PTR_FORMAT, config); if (pool->allocator) gst_object_unref (pool->allocator); pool->allocator = NULL; switch (obj->mode) { case GST_V4L2_IO_DMABUF: pool->allocator = gst_dmabuf_allocator_new (); can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, MMAP); break; case GST_V4L2_IO_MMAP: can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, MMAP); break; case GST_V4L2_IO_USERPTR: can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, USERPTR); break; case GST_V4L2_IO_DMABUF_IMPORT: can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, DMABUF); break; case GST_V4L2_IO_RW: pool->allocator = g_object_ref (allocator); pool->params = params; /* No need to change the configuration */ goto done; break; default: g_assert_not_reached (); break; } if (min_buffers < GST_V4L2_MIN_BUFFERS) { updated = TRUE; min_buffers = GST_V4L2_MIN_BUFFERS; GST_INFO_OBJECT (pool, "increasing minimum buffers to %u", min_buffers); } if (max_buffers > VIDEO_MAX_FRAME || max_buffers == 0) { updated = TRUE; max_buffers = VIDEO_MAX_FRAME; GST_INFO_OBJECT (pool, "reducing maximum buffers to %u", max_buffers); } if (min_buffers > max_buffers) { updated = TRUE; min_buffers = max_buffers; GST_INFO_OBJECT (pool, "reducing minimum buffers to %u", min_buffers); } else if (min_buffers != max_buffers) { if (!can_allocate) { updated = TRUE; max_buffers = min_buffers; GST_INFO_OBJECT (pool, "can't allocate, setting maximum to minimum"); } } if (!pool->add_videometa && obj->need_video_meta) { GST_INFO_OBJECT (pool, "adding needed video meta"); updated = TRUE; gst_buffer_pool_config_add_option (config, GST_BUFFER_POOL_OPTION_VIDEO_META); } if (updated) gst_buffer_pool_config_set_params (config, caps, size, min_buffers, max_buffers); /* keep a GstVideoInfo with defaults for the when we need to copy */ gst_video_info_from_caps (&pool->caps_info, caps); done: ret = GST_BUFFER_POOL_CLASS (parent_class)->set_config (bpool, config); /* If anything was changed documentation recommand to return FALSE */ return !updated && ret; /* ERRORS */ wrong_config: { GST_ERROR_OBJECT (pool, "invalid config %" GST_PTR_FORMAT, config); return FALSE; } }
static gboolean gst_v4l2_buffer_pool_start (GstBufferPool * bpool) { GstV4l2BufferPool *pool = GST_V4L2_BUFFER_POOL (bpool); GstBufferPoolClass *pclass = GST_BUFFER_POOL_CLASS (parent_class); GstV4l2Object *obj = pool->obj; GstStructure *config; GstCaps *caps; guint size, min_buffers, max_buffers; guint max_latency, min_latency, copy_threshold = 0; gboolean can_allocate = FALSE; GST_DEBUG_OBJECT (pool, "activating pool"); config = gst_buffer_pool_get_config (bpool); if (!gst_buffer_pool_config_get_params (config, &caps, &size, &min_buffers, &max_buffers)) goto wrong_config; min_latency = MAX (GST_V4L2_MIN_BUFFERS, obj->min_buffers); switch (obj->mode) { case GST_V4L2_IO_RW: can_allocate = TRUE; break; case GST_V4L2_IO_DMABUF: case GST_V4L2_IO_MMAP: { guint count; can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, MMAP); /* first, lets request buffers, and see how many we can get: */ GST_DEBUG_OBJECT (pool, "requesting %d MMAP buffers", min_buffers); count = gst_v4l2_allocator_start (pool->vallocator, min_buffers, V4L2_MEMORY_MMAP); if (count < GST_V4L2_MIN_BUFFERS) { min_buffers = count; goto no_buffers; } /* V4L2 buffer pool are often very limited in the amount of buffers it * can offer. The copy_threshold will workaround this limitation by * falling back to copy if the pipeline needed more buffers. This also * prevent having to do REQBUFS(N)/REQBUFS(0) everytime configure is * called. */ if (count != min_buffers) { GST_WARNING_OBJECT (pool, "using %u buffers instead of %u", count, min_buffers); min_buffers = count; copy_threshold = min_latency; /* The initial minimum could be provide either by GstBufferPool or * driver needs. */ min_buffers = count; } break; } case GST_V4L2_IO_USERPTR: { guint count; can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, USERPTR); GST_DEBUG_OBJECT (pool, "requesting %d USERPTR buffers", min_buffers); count = gst_v4l2_allocator_start (pool->vallocator, min_buffers, V4L2_MEMORY_USERPTR); /* There is no rational to not get what we asked */ if (count < min_buffers) { min_buffers = count; goto no_buffers; } min_buffers = count; break; } case GST_V4L2_IO_DMABUF_IMPORT: { guint count; can_allocate = GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, DMABUF); GST_DEBUG_OBJECT (pool, "requesting %d DMABUF buffers", min_buffers); count = gst_v4l2_allocator_start (pool->vallocator, min_buffers, V4L2_MEMORY_DMABUF); /* There is no rational to not get what we asked */ if (count < min_buffers) { min_buffers = count; goto no_buffers; } min_buffers = count; break; } default: min_buffers = 0; copy_threshold = 0; g_assert_not_reached (); break; } if (can_allocate) max_latency = max_buffers; else max_latency = min_buffers; pool->size = size; pool->copy_threshold = copy_threshold; pool->max_latency = max_latency; pool->min_latency = min_latency; pool->num_queued = 0; if (max_buffers < min_buffers) max_buffers = min_buffers; gst_buffer_pool_config_set_params (config, caps, size, min_buffers, max_buffers); pclass->set_config (bpool, config); gst_structure_free (config); if (pool->other_pool) if (!gst_buffer_pool_set_active (pool->other_pool, TRUE)) goto other_pool_failed; /* now, allocate the buffers: */ if (!pclass->start (bpool)) goto start_failed; if (!V4L2_TYPE_IS_OUTPUT (obj->type)) pool->group_released_handler = g_signal_connect_swapped (pool->vallocator, "group-released", G_CALLBACK (gst_v4l2_buffer_pool_group_released), pool); return TRUE; /* ERRORS */ wrong_config: { GST_ERROR_OBJECT (pool, "invalid config %" GST_PTR_FORMAT, config); gst_structure_free (config); return FALSE; } no_buffers: { GST_ERROR_OBJECT (pool, "we received %d buffer from device '%s', we want at least %d", min_buffers, obj->videodev, GST_V4L2_MIN_BUFFERS); gst_structure_free (config); return FALSE; } start_failed: { GST_ERROR_OBJECT (pool, "failed to start streaming"); return FALSE; } other_pool_failed: { GST_ERROR_OBJECT (pool, "failed to active the other pool %" GST_PTR_FORMAT, pool->other_pool); return FALSE; } }
/** * gst_v4l2_buffer_pool_process: * @bpool: a #GstBufferPool * @buf: a #GstBuffer, maybe be replaced * * Process @buf in @bpool. For capture devices, this functions fills @buf with * data from the device. For output devices, this functions send the contents of * @buf to the device for playback. * * Returns: %GST_FLOW_OK on success. */ GstFlowReturn gst_v4l2_buffer_pool_process (GstV4l2BufferPool * pool, GstBuffer ** buf) { GstFlowReturn ret = GST_FLOW_OK; GstBufferPool *bpool = GST_BUFFER_POOL_CAST (pool); GstV4l2Object *obj = pool->obj; GST_DEBUG_OBJECT (pool, "process buffer %p", buf); g_return_val_if_fail (gst_buffer_pool_is_active (bpool), GST_FLOW_ERROR); if (GST_BUFFER_POOL_IS_FLUSHING (pool)) return GST_FLOW_FLUSHING; switch (obj->type) { case V4L2_BUF_TYPE_VIDEO_CAPTURE: case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE: /* capture */ switch (obj->mode) { case GST_V4L2_IO_RW: /* capture into the buffer */ ret = gst_v4l2_do_read (pool, *buf); break; case GST_V4L2_IO_MMAP: case GST_V4L2_IO_DMABUF: { GstBuffer *tmp; if ((*buf)->pool == bpool) { if (gst_buffer_get_size (*buf) == 0) goto eos; /* start copying buffers when we are running low on buffers */ if (g_atomic_int_get (&pool->num_queued) < pool->copy_threshold) { GstBuffer *copy; if (GST_V4L2_ALLOCATOR_CAN_ALLOCATE (pool->vallocator, MMAP)) { if (gst_buffer_pool_acquire_buffer (bpool, ©, NULL) == GST_FLOW_OK) { gst_v4l2_buffer_pool_release_buffer (bpool, copy); goto done; } } /* copy the buffer */ copy = gst_buffer_copy_region (*buf, GST_BUFFER_COPY_ALL | GST_BUFFER_COPY_DEEP, 0, -1); GST_LOG_OBJECT (pool, "copy buffer %p->%p", *buf, copy); /* and requeue so that we can continue capturing */ gst_buffer_unref (*buf); *buf = copy; } /* nothing, data was inside the buffer when we did _acquire() */ goto done; } /* buffer not from our pool, grab a frame and copy it into the target */ if ((ret = gst_v4l2_buffer_pool_dqbuf (pool, &tmp)) != GST_FLOW_OK) goto done; /* An empty buffer on capture indicates the end of stream */ if (gst_buffer_get_size (tmp) == 0) { gst_v4l2_buffer_pool_release_buffer (bpool, tmp); goto eos; } ret = gst_v4l2_buffer_pool_copy_buffer (pool, *buf, tmp); /* an queue the buffer again after the copy */ gst_v4l2_buffer_pool_release_buffer (bpool, tmp); if (ret != GST_FLOW_OK) goto copy_failed; break; } case GST_V4L2_IO_USERPTR: { struct UserPtrData *data; /* Replace our buffer with downstream allocated buffer */ data = gst_mini_object_steal_qdata (GST_MINI_OBJECT (*buf), GST_V4L2_IMPORT_QUARK); gst_buffer_replace (buf, data->buffer); _unmap_userptr_frame (data); break; } case GST_V4L2_IO_DMABUF_IMPORT: { GstBuffer *tmp; /* Replace our buffer with downstream allocated buffer */ tmp = gst_mini_object_steal_qdata (GST_MINI_OBJECT (*buf), GST_V4L2_IMPORT_QUARK); gst_buffer_replace (buf, tmp); gst_buffer_unref (tmp); break; } default: g_assert_not_reached (); break; } break; case V4L2_BUF_TYPE_VIDEO_OUTPUT: case V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE: /* playback */ switch (obj->mode) { case GST_V4L2_IO_RW: /* FIXME, do write() */ GST_WARNING_OBJECT (pool, "implement write()"); break; case GST_V4L2_IO_USERPTR: case GST_V4L2_IO_DMABUF_IMPORT: case GST_V4L2_IO_DMABUF: case GST_V4L2_IO_MMAP: { GstBuffer *to_queue = NULL; GstV4l2MemoryGroup *group; gint index; if ((*buf)->pool != bpool) goto copying; if (!gst_v4l2_is_buffer_valid (*buf, &group)) goto copying; index = group->buffer.index; GST_LOG_OBJECT (pool, "processing buffer %i from our pool", index); index = group->buffer.index; if (pool->buffers[index] != NULL) { GST_LOG_OBJECT (pool, "buffer %i already queued, copying", index); goto copying; } /* we can queue directly */ to_queue = gst_buffer_ref (*buf); copying: if (to_queue == NULL) { GstBufferPoolAcquireParams params = { 0 }; GST_LOG_OBJECT (pool, "alloc buffer from our pool"); /* this can return EOS if all buffers are outstanding which would * be strange because we would expect the upstream element to have * allocated them and returned to us.. */ params.flags = GST_BUFFER_POOL_ACQUIRE_FLAG_DONTWAIT; ret = gst_buffer_pool_acquire_buffer (bpool, &to_queue, ¶ms); if (ret != GST_FLOW_OK) goto acquire_failed; ret = gst_v4l2_buffer_pool_prepare_buffer (pool, to_queue, *buf); if (ret != GST_FLOW_OK) { gst_buffer_unref (to_queue); goto prepare_failed; } } if ((ret = gst_v4l2_buffer_pool_qbuf (pool, to_queue)) != GST_FLOW_OK) goto queue_failed; /* if we are not streaming yet (this is the first buffer, start * streaming now */ if (!gst_v4l2_buffer_pool_streamon (pool)) { /* don't check return value because qbuf would have failed */ gst_v4l2_is_buffer_valid (to_queue, &group); /* qbuf has taken the ref of the to_queue buffer but we are no in * streaming state, so the flush logic won't be performed. * To avoid leaks, flush the allocator and restore the queued * buffer as non-queued */ gst_v4l2_allocator_flush (pool->vallocator); pool->buffers[group->buffer.index] = NULL; gst_mini_object_set_qdata (GST_MINI_OBJECT (to_queue), GST_V4L2_IMPORT_QUARK, NULL, NULL); gst_buffer_unref (to_queue); g_atomic_int_add (&pool->num_queued, -1); goto start_failed; } if (g_atomic_int_get (&pool->num_queued) >= pool->min_latency) { GstBuffer *out; /* all buffers are queued, try to dequeue one and release it back * into the pool so that _acquire can get to it again. */ ret = gst_v4l2_buffer_pool_dqbuf (pool, &out); if (ret == GST_FLOW_OK) /* release the rendered buffer back into the pool. This wakes up any * thread waiting for a buffer in _acquire(). */ gst_buffer_unref (out); } break; } default: g_assert_not_reached (); break; } break; default: g_assert_not_reached (); break; } done: return ret; /* ERRORS */ copy_failed: { GST_ERROR_OBJECT (pool, "failed to copy buffer"); return ret; } eos: { GST_DEBUG_OBJECT (pool, "end of stream reached"); return GST_FLOW_EOS; } acquire_failed: { if (ret == GST_FLOW_FLUSHING) GST_DEBUG_OBJECT (pool, "flushing"); else GST_WARNING_OBJECT (pool, "failed to acquire a buffer: %s", gst_flow_get_name (ret)); return ret; } prepare_failed: { GST_ERROR_OBJECT (pool, "failed to prepare data"); return ret; } queue_failed: { GST_ERROR_OBJECT (pool, "failed to queue buffer"); return ret; } start_failed: { GST_ERROR_OBJECT (pool, "failed to start streaming"); return GST_FLOW_ERROR; } }