lavc: Add coded bitstream read/write API

1 files changed, 460 insertions, 0 deletions

diff --git a/libavcodec/cbs.c b/libavcodec/cbs.c
new file mode 100644
index 0000000000..3a205c393d
--- /dev/null
+++ b/libavcodec/cbs.c
@@ -0,0 +1,460 @@
+/*
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <string.h>
+
+#include "config.h"
+
+#include "libavutil/avassert.h"
+#include "libavutil/common.h"
+
+#include "cbs.h"
+#include "cbs_internal.h"
+
+
+static const CodedBitstreamType *cbs_type_table[] = {
+};
+
+int ff_cbs_init(CodedBitstreamContext *ctx,
+                enum AVCodecID codec_id, void *log_ctx)
+{
+    const CodedBitstreamType *type;
+    int i;
+
+    type = NULL;
+    for (i = 0; i < FF_ARRAY_ELEMS(cbs_type_table); i++) {
+        if (cbs_type_table[i]->codec_id == codec_id) {
+            type = cbs_type_table[i];
+            break;
+        }
+    }
+    if (!type)
+        return AVERROR(EINVAL);
+
+    ctx->log_ctx = log_ctx;
+    ctx->codec   = type;
+
+    ctx->priv_data = av_mallocz(ctx->codec->priv_data_size);
+    if (!ctx->priv_data)
+        return AVERROR(ENOMEM);
+
+    ctx->decompose_unit_types = NULL;
+
+    ctx->trace_enable = 0;
+    ctx->trace_level  = AV_LOG_TRACE;
+
+    return 0;
+}
+
+void ff_cbs_close(CodedBitstreamContext *ctx)
+{
+    if (ctx->codec && ctx->codec->close)
+        ctx->codec->close(ctx);
+
+    av_freep(&ctx->priv_data);
+}
+
+static void cbs_unit_uninit(CodedBitstreamContext *ctx,
+                            CodedBitstreamUnit *unit)
+{
+    if (ctx->codec->free_unit && unit->content && !unit->content_external)
+        ctx->codec->free_unit(unit);
+
+    av_freep(&unit->data);
+    unit->data_size = 0;
+    unit->data_bit_padding = 0;
+}
+
+void ff_cbs_fragment_uninit(CodedBitstreamContext *ctx,
+                            CodedBitstreamFragment *frag)
+{
+    int i;
+
+    for (i = 0; i < frag->nb_units; i++)
+        cbs_unit_uninit(ctx, &frag->units[i]);
+    av_freep(&frag->units);
+    frag->nb_units = 0;
+
+    av_freep(&frag->data);
+    frag->data_size        = 0;
+    frag->data_bit_padding = 0;
+}
+
+static int cbs_read_fragment_content(CodedBitstreamContext *ctx,
+                                     CodedBitstreamFragment *frag)
+{
+    int err, i, j;
+
+    for (i = 0; i < frag->nb_units; i++) {
+        if (ctx->decompose_unit_types) {
+            for (j = 0; j < ctx->nb_decompose_unit_types; j++) {
+                if (ctx->decompose_unit_types[j] == frag->units[i].type)
+                    break;
+            }
+            if (j >= ctx->nb_decompose_unit_types)
+                continue;
+        }
+
+        err = ctx->codec->read_unit(ctx, &frag->units[i]);
+        if (err == AVERROR(ENOSYS)) {
+            av_log(ctx->log_ctx, AV_LOG_WARNING,
+                   "Decomposition unimplemented for unit %d "
+                   "(type %d).\n", i, frag->units[i].type);
+        } else if (err < 0) {
+            av_log(ctx->log_ctx, AV_LOG_ERROR, "Failed to read unit %d "
+                   "(type %d).\n", i, frag->units[i].type);
+            return err;
+        }
+    }
+
+    return 0;
+}
+
+int ff_cbs_read_extradata(CodedBitstreamContext *ctx,
+                          CodedBitstreamFragment *frag,
+                          const AVCodecParameters *par)
+{
+    int err;
+
+    memset(frag, 0, sizeof(*frag));
+
+    frag->data      = par->extradata;
+    frag->data_size = par->extradata_size;
+
+    err = ctx->codec->split_fragment(ctx, frag, 1);
+    if (err < 0)
+        return err;
+
+    frag->data      = NULL;
+    frag->data_size = 0;
+
+    return cbs_read_fragment_content(ctx, frag);
+}
+
+int ff_cbs_read_packet(CodedBitstreamContext *ctx,
+                       CodedBitstreamFragment *frag,
+                       const AVPacket *pkt)
+{
+    int err;
+
+    memset(frag, 0, sizeof(*frag));
+
+    frag->data      = pkt->data;
+    frag->data_size = pkt->size;
+
+    err = ctx->codec->split_fragment(ctx, frag, 0);
+    if (err < 0)
+        return err;
+
+    frag->data      = NULL;
+    frag->data_size = 0;
+
+    return cbs_read_fragment_content(ctx, frag);
+}
+
+int ff_cbs_read(CodedBitstreamContext *ctx,
+                CodedBitstreamFragment *frag,
+                const uint8_t *data, size_t size)
+{
+    int err;
+
+    memset(frag, 0, sizeof(*frag));
+
+    // (We won't write to this during split.)
+    frag->data      = (uint8_t*)data;
+    frag->data_size = size;
+
+    err = ctx->codec->split_fragment(ctx, frag, 0);
+    if (err < 0)
+        return err;
+
+    frag->data      = NULL;
+    frag->data_size = 0;
+
+    return cbs_read_fragment_content(ctx, frag);
+}
+
+
+int ff_cbs_write_fragment_data(CodedBitstreamContext *ctx,
+                               CodedBitstreamFragment *frag)
+{
+    int err, i;
+
+    for (i = 0; i < frag->nb_units; i++) {
+        if (!frag->units[i].content)
+            continue;
+
+        err = ctx->codec->write_unit(ctx, &frag->units[i]);
+        if (err < 0) {
+            av_log(ctx->log_ctx, AV_LOG_ERROR, "Failed to write unit %d "
+                   "(type %d).\n", i, frag->units[i].type);
+            return err;
+        }
+    }
+
+    err = ctx->codec->assemble_fragment(ctx, frag);
+    if (err < 0) {
+        av_log(ctx->log_ctx, AV_LOG_ERROR, "Failed to assemble fragment.\n");
+        return err;
+    }
+
+    return 0;
+}
+
+int ff_cbs_write_extradata(CodedBitstreamContext *ctx,
+                           AVCodecParameters *par,
+                           CodedBitstreamFragment *frag)
+{
+    int err;
+
+    err = ff_cbs_write_fragment_data(ctx, frag);
+    if (err < 0)
+        return err;
+
+    av_freep(&par->extradata);
+
+    par->extradata = av_malloc(frag->data_size +
+                               AV_INPUT_BUFFER_PADDING_SIZE);
+    if (!par->extradata)
+        return AVERROR(ENOMEM);
+
+    memcpy(par->extradata, frag->data, frag->data_size);
+    memset(par->extradata + frag->data_size, 0,
+           AV_INPUT_BUFFER_PADDING_SIZE);
+    par->extradata_size = frag->data_size;
+
+    return 0;
+}
+
+int ff_cbs_write_packet(CodedBitstreamContext *ctx,
+                        AVPacket *pkt,
+                        CodedBitstreamFragment *frag)
+{
+    int err;
+
+    err = ff_cbs_write_fragment_data(ctx, frag);
+    if (err < 0)
+        return err;
+
+    av_new_packet(pkt, frag->data_size);
+    if (err < 0)
+        return err;
+
+    memcpy(pkt->data, frag->data, frag->data_size);
+    pkt->size = frag->data_size;
+
+    return 0;
+}
+
+
+void ff_cbs_trace_header(CodedBitstreamContext *ctx,
+                         const char *name)
+{
+    if (!ctx->trace_enable)
+        return;
+
+    av_log(ctx->log_ctx, ctx->trace_level, "%s\n", name);
+}
+
+void ff_cbs_trace_syntax_element(CodedBitstreamContext *ctx, int position,
+                                 const char *name, const char *bits,
+                                 int64_t value)
+{
+    size_t name_len, bits_len;
+    int pad;
+
+    if (!ctx->trace_enable)
+        return;
+
+    av_assert0(value >= INT_MIN && value <= UINT32_MAX);
+
+    name_len = strlen(name);
+    bits_len = strlen(bits);
+
+    if (name_len + bits_len > 60)
+        pad = bits_len + 2;
+    else
+        pad = 61 - name_len;
+
+    av_log(ctx->log_ctx, ctx->trace_level, "%-10d  %s%*s = %"PRId64"\n",
+           position, name, pad, bits, value);
+}
+
+int ff_cbs_read_unsigned(CodedBitstreamContext *ctx, BitstreamContext *bc,
+                         int width, const char *name, uint32_t *write_to,
+                         uint32_t range_min, uint32_t range_max)
+{
+    uint32_t value;
+    int position;
+
+    av_assert0(width <= 32);
+
+    if (ctx->trace_enable)
+        position = bitstream_tell(bc);
+
+    value = bitstream_read(bc, width);
+
+    if (ctx->trace_enable) {
+        char bits[33];
+        int i;
+        for (i = 0; i < width; i++)
+            bits[i] = value >> (width - i - 1) & 1 ? '1' : '0';
+        bits[i] = 0;
+
+        ff_cbs_trace_syntax_element(ctx, position, name, bits, value);
+    }
+
+    if (value < range_min || value > range_max) {
+        av_log(ctx->log_ctx, AV_LOG_ERROR, "%s out of range: "
+               "%"PRIu32", but must be in [%"PRIu32",%"PRIu32"].\n",
+               name, value, range_min, range_max);
+        return AVERROR_INVALIDDATA;
+    }
+
+    *write_to = value;
+    return 0;
+}
+
+int ff_cbs_write_unsigned(CodedBitstreamContext *ctx, PutBitContext *pbc,
+                          int width, const char *name, uint32_t value,
+                          uint32_t range_min, uint32_t range_max)
+{
+    av_assert0(width <= 32);
+
+    if (value < range_min || value > range_max) {
+        av_log(ctx->log_ctx, AV_LOG_ERROR, "%s out of range: "
+               "%"PRIu32", but must be in [%"PRIu32",%"PRIu32"].\n",
+               name, value, range_min, range_max);
+        return AVERROR_INVALIDDATA;
+    }
+
+    if (put_bits_left(pbc) < width)
+        return AVERROR(ENOSPC);
+
+    if (ctx->trace_enable) {
+        char bits[33];
+        int i;
+        for (i = 0; i < width; i++)
+            bits[i] = value >> (width - i - 1) & 1 ? '1' : '0';
+        bits[i] = 0;
+
+        ff_cbs_trace_syntax_element(ctx, put_bits_count(pbc), name, bits, value);
+    }
+
+    if (width < 32)
+        put_bits(pbc, width, value);
+    else
+        put_bits32(pbc, value);
+
+    return 0;
+}
+
+
+static int cbs_insert_unit(CodedBitstreamContext *ctx,
+                           CodedBitstreamFragment *frag,
+                           int position)
+{
+    CodedBitstreamUnit *units;
+
+    units = av_malloc_array(frag->nb_units + 1, sizeof(*units));
+    if (!units)
+        return AVERROR(ENOMEM);
+
+    if (position > 0)
+        memcpy(units, frag->units, position * sizeof(*units));
+    if (position < frag->nb_units)
+        memcpy(units + position + 1, frag->units + position,
+               (frag->nb_units - position) * sizeof(*units));
+
+    memset(units + position, 0, sizeof(*units));
+
+    av_freep(&frag->units);
+    frag->units = units;
+    ++frag->nb_units;
+
+    return 0;
+}
+
+int ff_cbs_insert_unit_content(CodedBitstreamContext *ctx,
+                               CodedBitstreamFragment *frag,
+                               int position, uint32_t type,
+                               void *content)
+{
+    int err;
+
+    if (position == -1)
+        position = frag->nb_units;
+    av_assert0(position >= 0 && position <= frag->nb_units);
+
+    err = cbs_insert_unit(ctx, frag, position);
+    if (err < 0)
+        return err;
+
+    frag->units[position].type             = type;
+    frag->units[position].content          = content;
+    frag->units[position].content_external = 1;
+
+    return 0;
+}
+
+int ff_cbs_insert_unit_data(CodedBitstreamContext *ctx,
+                            CodedBitstreamFragment *frag,
+                            int position, uint32_t type,
+                            uint8_t *data, size_t data_size)
+{
+    int err;
+
+    if (position == -1)
+        position = frag->nb_units;
+    av_assert0(position >= 0 && position <= frag->nb_units);
+
+    err = cbs_insert_unit(ctx, frag, position);
+    if (err < 0)
+        return err;
+
+    frag->units[position].type      = type;
+    frag->units[position].data      = data;
+    frag->units[position].data_size = data_size;
+
+    return 0;
+}
+
+int ff_cbs_delete_unit(CodedBitstreamContext *ctx,
+                       CodedBitstreamFragment *frag,
+                       int position)
+{
+    if (position < 0 || position >= frag->nb_units)
+        return AVERROR(EINVAL);
+
+    cbs_unit_uninit(ctx, &frag->units[position]);
+
+    --frag->nb_units;
+
+    if (frag->nb_units == 0) {
+        av_freep(&frag->units);
+
+    } else {
+        memmove(frag->units + position,
+                frag->units + position + 1,
+                (frag->nb_units - position) * sizeof(*frag->units));
+
+        // Don't bother reallocating the unit array.
+    }
+
+    return 0;
+}